Full opinion text
PER CURIAM. Following the death of Shauna Farrow and the wounding of Derrick Smith, Yancy Lyndell Douglas and Paris LaPriest Powell were each convicted of first degree malice murder and shooting with intent to kill. Mr. Douglas and Mr. Powell were tried separately, almost two years apart, and both juries found that their respective defendants knowingly created a great risk of death to more than one person. Both juries also assessed the death penalty to their defendants for the murder of Shauna Farrow, and sentenced them to life imprisonment for the shooting of Derrick Smith. Smith was the key witness at both trials. Both defendants exhausted their state court remedies. Douglas v. State, 951 P.2d 651 (Okla.Crim.App.1997) (Douglas I) (direct appeal); Douglas v. State, 953 P.2d 349 (Okla.Crim.App.1998) (Douglas II) (collateral review); Powell v. State, 995 P.2d 510 (Okla.Crim.App.2000) (direct appeal) (Powell I)', Powell v. State, PCD-1999-719 (Okla.Crim.App. Mar. 17, 2000) (Powell II) (collateral review). The defendants then initiated federal habeas proceedings. In his federal habeas petition filed on August 2, 1999, Mr. Douglas asserted that numerous constitutional errors infected his trial. The district court denied the petition. Douglas v. Gibson, No. CIV-99-75C (W.D.Okla. Jan. 10, 2001) (Douglas III). Before Mr. Douglas’s appeal was heard in this court, however, Smith recanted his identification of Mr. Douglas and Mr. Powell and alleged that the prosecuting attorney, Brad Miller, had suborned perjured testimony from him, which he provided in exchange for favorable treatment, and that Miller had also elicited false testimony from him denying the existence of any deal for his testimony. On December 12, 2001, we granted Mr. Douglas’s request to file a second habeas petition pursuant to 28 U.S.C. § 2244(b)(3)(c) and we abated his pending appeal of the first petition. On September 20, 2001, Mr. Powell filed his federal habeas petition incorporating allegations concerning the newly discovered evidence. After a joint evidentiary hearing was held on the new allegations in the Douglas and Powell petitions, the district court granted Mr. Powell’s petition and denied Mr. Douglas’s. On appeal, Mr. Douglas asserts, inter alia, due process claims relating to the prosecutor’s egregious conduct when he vouched for the credibility of the key witness, Derrick Smith, by using false testimony he elicited from Smith, suppressed exculpatory evidence of his agreement to assist Smith with his numerous legal difficulties in exchange for his favorable testimony, and failed to correct Smith’s false testimony that no deals were made. The State of Oklahoma appeals the grant of Mr. Powell’s petition, and Mr. Powell cross-appeals the conditional nature of the writ granted to him. We consolidated the appeals. We affirm the district court’s order granting Mr. Powell conditional ha-beas relief. We reverse the district court’s refusal to grant habeas relief to Mr. Douglas, and we remand to the district court with instructions to grant the writ as to Mr. Douglas’s convictions and sentence, subject to the State’s right to retry him. I The Murder Derrick Smith, a member of the Southeast Village Crips, spent the afternoon and evening of June 24, 1993, with his friends at the Ambassador Court Apartments in Oklahoma City. Smith, then seventeen, was drinking alcohol and smoking numerous marijuana joints with his gang associates. Fourteen-year-old Shauna Farrow was also at the apartment complex. Around 11:00 p.m., Smith began riding his bike home. When he caught up with Farrow, who had left shortly before, he dismounted his bike to walk along with her. Other than the light from nearby porch lamps, it was a dark night. According to Smith’s testimony at the trials, he and Farrow were passed from behind by a grey Datsun hatchback playing loud rap music. The car turned around at the end of the block and came slowly back toward them, the music no longer playing. Just as the car passed Smith and Farrow, it stopped and the driver’s side door opened. Smith saw the driver and front passenger were crouched forward, as though to let the rear passenger exit the car. Smith saw something chrome in the driver’s hand aimed at him, and then saw flashes as gunfire came from the car’s occupants. Smith was hit once in the left hip and fell over his bicycle onto the nearby grass. Farrow was backing away with her hands raised when she was hit in the chest and killed. When Smith saw Farrow collapse, he glanced quickly at the car, saw continued gunfire, and buried his face in the ground and closed his eyes. Smith was carrying a loaded .380 semiautomatic pistol; however, he was so inebriated that he forgot he was armed. After the shooting stopped, Smith heard the ear door shut and one of the shooters say “Fuck 'em” as the car drove away. Smith testified at trial that he recognized the voice as Mr. Douglas’s. Smith crawled behind a camper trailer parked in a nearby driveway. From there, he testified he saw the assailants’ car stop at a driveway seven houses down the street. The car doors opened and closed again, and the car drove away. As Smith was crawling, a bag of crack cocaine fell out of his pocket. Smith threw his gun into the backyard of the house and laid in the yard between the houses until the police and ambulance arrived. Later investigation of the crime scene revealed bullets and casings from three different weapons used in the assault. Smith’s weapon was never recovered. Earlier on the night of June 24, LaDana and Winter Milton and their friend Ebony Rhone saw Yancy Douglas and other members of the 107 Hoover Crips at Pitts Park. The young men were excited and were talking of shooting someone on the south side of Oklahoma City. The girls watched Mr. Douglas leave the park in a two-door hatchback. As he left, he fired his gun out of the window of the vehicle. Between 12:00 and 1:00 a.m. on June 25, Yancy Douglas drove Paris Powell to the home of Lawrence Kuykendoll. Mr. Powell had been shot in the left hand, and Kuykendoll took him to the hospital. Mr. Douglas left Kuykendoll’s home in the blue two-door Plymouth hatchback in which he and Mr. Powell had arrived. Mr. Powell was hospitalized for two days and then released into police custody. On the afternoon of June 25, Mr. Douglas drove the blue hatchback to Leon Washington’s body shop, apparently at Mr. Powell’s request. Douglas IV at 21. Pre-Trial Developments Smith made several statements to the Oklahoma City police shortly after the shooting. At 12:50 a.m. on June 25, he told Officer Williams that four black men in a four-door blue or grey Datsun shot at him and Farrow, and he identified Paris Powell, a member of the 107 Hoover Crips, as the car’s driver. Before his surgery later that day, Smith repeated to Detective Mullenix his identification of Mr. Powell as the driver, although Smith said he was only fifty percent certain Mr. Powell was in the car. He also told Detective Mulle-nix that Anthony Hishaw and Yancy Douglas were passengers in the car. Finally, shortly after his surgery, Smith gave Officer Dycus several conflicting versions of the previous night’s events. First he stated that Mr. Powell was driving the vehicle, then that Mr. Douglas was. Smith also said he believed the car was Hishaw’s and that Hishaw was in the vehicle the night of the shooting. Hishaw was, in fact, in prison on June 24 and 25, 1993. Smith testified he had seen Mr. Powell in the vehicle before as well. He told Officer Dycus he thought there were seven or eight people in the car, but then changed his story when the officer said he did not believe Smith was telling the truth. Smith finally said there were four occupants, that Mr. Powell was driving, that Mr. Douglas was in the front passenger seat, and that there were two other passengers he could not identify. In none of his statements to the police did Smith mention the ear stopping in a nearby driveway. At the preliminary hearing on August 27,1993, Smith testified in a manner largely consistent with what his later trial testimony would be: that he was certain Mr. Powell was the driver and one of the shooters, that the ear stopped in a driveway up the street from the shooting, and that he guessed the car stopped to allow a change of driver. However, Smith described the assailants’ car as a grey Dat-sun with black louvers on the rear window. Based on how the car sounded as it drove away, Smith was certain that it had a standard transmission. At the time of the preliminary hearing, the police had not located the vehicle used during the shooting. At the time of the shooting, Smith was facing pending charges in a 1992 cocaine trafficking case. By the time of the preliminary hearing for Mr. Powell and Mr. Douglas in August 1993, Smith had also been charged with throwing a rock at a police car. As part of a plea bargain, Smith pled guilty in the drug case on February 1, 1994, receiving a sentence of 10 years on a reduced charge of possession with intent to distribute, while the charge in the rock throwing incident was dismissed. Powell III at 6. In June 1994, after serving four months of his ten-year sentence, Smith was released on pre-pa-role under the supervision of the Oklahoma Department of Corrections (ODOC). Id. Smith’s pre-parole status was revoked, however, and he was reincarcerated after he was arrested in September 1994 for receiving stolen property. Id. In March 1995, the police located the vehicle they believed was driven by the assailants on the night of Farrow’s murder. The vehicle that would become State Trial Exhibit 2 was not a grey Datsun with black rear-window louvers, standard transmission, and a loud stereo, but rather a light blue Dodge Omni with no window louvers, an automatic transmission, and no stereo. Also in March 1995, Smith became aware that he would again be considered for pre-parole release during the parole board’s July 1995 docket. A parole board investigator interviewed Smith on May 22, 1995, in preparation for the July review, but issued a negative recommendation on pre-parole based on Smith’s history of reincarceration and failure to complete prison programs. In final preparation for Mr. Douglas’s trial, Assistant District Attorney Brad Miller, who would prosecute both Mr. Douglas and Mr. Powell, issued a writ of habeas corpus ad prosequendum, for Smith, releasing him from ODOC custody so he could testify about the shooting. Miller wrote a note in his file on May 25, 1995, three days after Smith’s pre-parole investí-gation interview, noting that he had caused the writ to issue and stating that he had spoken to Smith about the murder case. This was apparently Miller and Smith’s first contact regarding the Douglas and Powell trials. Mr. Douglas’s Trial Mr. Douglas’s trial began on June 20, 1995, with Miller as the lead prosecutor. Smith’s testimony, and, in particular, his identification of Mr. Powell and Mr. Douglas as the shooters, was the “linchpin” of the prosecution’s case. Douglas IV at 21. For example, he identified State Trial Exhibit 2 as the car driven by the shooters despite the apparent inconsistencies with his prior descriptions of it. Miller elicited testimony from Smith denying there was any deal for Smith’s testimony or even any discussions of help from the District Attorney’s office. On cross-examination, Smith further denied any quid pro quo for his testimony, including a denial that he expected Miller to write a letter to the parole board approving his application for pre-paróle status. Indeed, on redirect, Miller elicited further testimony that Smith never asked Miller to help him and that Smith received no special treatment on the charges he faced prior to Douglas’s trial. Mr. Douglas presented an alibi defense at trial. He testified that he spent the day of the shooting at his mother’s apartment, leaving only after midnight when two fellow members of the 107 Hoover Crips drove Paris Powell to his house and told him that Mr. Powell had been shot. Mr. Douglas testified that he got into their car with Mr. Powell, who asked Mr. Douglas to drive him to Lawrence Kuykendoll’s house so that Kuykendoll could take Mr. Powell to the hospital. After dropping him off, Mr. Douglas testified that he spent the night at Kim Barnett’s house, arriving sometime after midnight. He also testified that the next day Mr. Powell contacted him by pager and asked him to take the car to Leon Washington’s body shop. Mr. Douglas did so that afternoon and was arrested later the same day. In his closing argument during the guilt phase of Mr. Douglas’s trial, Miller emphasized that Smith’s testimony was trustworthy because there was no quid pro quo between Smith and Miller. Miller pointed to the ten-year sentence Smith received on the reduced distribution charge as evidence there was no deal, and contended Smith’s admission that he was carrying drugs and a gun when he was shot indicated there was no deal. Miller then implored the jury members to ask yourself if you have seen anything that would indicate to you that anybody’s trying to convict someone that’s not guilty, trying to be unfair. Ask yourself again, do you think we don’t have enough to do over there in the D.A.’s office not to try to work this hard to convict someone that’s innocent? Douglas Trial Tr. at 1870-71. Miller made a number of additional comments during his cross-examination and his guilt-phase closing argument with which Mr. Douglas takes issue in his habeas petition and this appeal; these statements will be more fully reviewed in the context of the prosecu-torial misconduct challenges Mr. Douglas asserts. Following the guilt-phase closing arguments and the court’s instructions, the jury convicted Mr. Douglas of one count of murder in the first degree, Okla. Stat., tit. 21 § 701.7(A), and one count of shooting with intent to kill, Okla. Stat., tit. 21 § 652. It then considered whether a death sentence was appropriate. During the penalty phase of Mr. Douglas’s trial, the prosecution sought to prove aggravating circumstances, including that Mr. Douglas “knowingly created a great risk of death to more than one person” and “the existence of a probability that [Mr. Douglas] would commit criminal acts of violence that would constitute a continuing threat to society,” pursuant to Okla. Stat. tit. 21 § 701.12(2) and (7). Douglas I, 951 P.2d at 658 n. 1. Mr. Douglas, in turn, presented mitigating evidence, including the testimony of Dr. Herman Jones, a psychologist who had examined him in 1992 to determine his amenability to rehabilitation in connection with a juvenile offense, but who had not seen him since that time. Id. at 680. Based in part on Jones’s testimony, defense counsel argued that Mr. Douglas did not pose a continuing threat. Id. In his closing arguments at the penalty phase, Miller made further comments to which Mr. Douglas objects. Of particular note, Miller told the jury that “[n]one of us has the job of sometime in the future carrying out the execution. There are other people that do that, if it ever happens. Your job is simply to make a decision with as much neutrality as you can about what’s appropriate in this case.” Douglas Trial Tr. at 2362. Discussing unadjudicated acts which he argued supported the continuing threat aggravating factor, Miller suggested to the jury that if you think for a minute that [Mr. Douglas] had — he had an excuse for any of these acts of misconduct, could he really show that he was actually physically, factually not guilty of something, anybody doubt that he would have done that? ... Bottom line, he couldn’t prove he wasn’t guilty because he was guilty. Id. at 2364. In addition, discussing a potential witness to one of these unadjudicat-ed acts who refused to testify, Miller noted that Charles McGee didn’t come in here. You know how difficult it is. You’ve heard from officers how difficult it is to get these people to cooperate with the police, even if they’ve been shot. There’s an example. Nevertheless, it doesn’t diminish — just because no one will cooperate — it doesn’t in any way diminish [Mr. Douglas’s] tendency toward violence and the proof that allows for his probability of violence in the future in whatever society that he’s in. Id. at 2314. And while discussing another unadjudicated act — a gang fight at the Crossroads Mall in which Mr. Douglas allegedly participated — Miller asked the jury, “Anybody know where they were 3-7 of '92? ... I don’t know where I was, but I could have been at Crossroads. My little kids could have been at Crossroads.” Id. at 2316. The jury agreed on two aggravators, the great risk of death to more than one person and the continuing threat to society. They recommended a sentence of death for the charge of first degree murder and life imprisonment for the charge of shooting with intent to kill. Post-Trial Developments and Mr. Powell’s Trial Just one day after Mr. Douglas’s trial concluded, Miller sent a letter to the parole board in support of Smith’s application for parole from his ten-year sentence for cocaine possession. Powell III at 7. In the letter, Miller maintained that his “office gave [Smith] no special treatment in his case. However, he was required to testify at [the] preliminary hearing and the trial of Yancy Douglas.... [H]e has fully cooperated and truthfully testified in both instances.” Id. Lauding Smith for “[standing] up like a responsible citizen,” the letter stated Smith was motivated by the “wrongness of Shawna’s [sic] death.” Id. Miller maintained he had no agreements with Smith but noted that Smith understood “that he will be required to testify in Paris Powell’s trial,” as well. Id. at 7-8. Smith was once again granted pre-parole status and released in October 1995. Id. at 8. Smith again violated the terms of his release and was reincarcerated in February 1996. On April 20,1997, still in ODOC custody, Smith wrote a letter to his mother. Id. at 8-9. In it, Smith asked her to contact Miller about his confinement: What’s up Momma? Have you been calling Cuz? Probably not man call O Dude and get that hook up to where I can come home from the county jail or tell him he’s short because I ain’t gone let him put me in the cross again like he did last time, but he ain’t gone to do shit if ya don’t continue to call him and let him know what’s going on, it’s fifteen days before the trial starts and I don’t wanna be up in that county jail if he ain’t talking write. Tell ‘em I want 365 days for helping the state to kill some body cause that’s what he plans to do.... Stay own brad miller and I’ll Holler at you’ll later. Id. On April 23, 1997, Brad Miller received a call from the home of Smith’s aunt, whose phone Smith’s mother commonly used. Apparently in response to the call, Miller telephoned David Petite, a sentence administration auditor at ODOC. Miller wrote the following notes regarding the call: “Warden Ron Ward”; “Derrick Smith”; “coop credits”; and “with credits - > 225 days = 11/11/97.” Id. at 9. None of this was disclosed to the defense. Mr. Powell’s trial on charges of first degree murder and shooting with intent to kill began one week after Miller’s call to ODOC. Id. Smith was again the State’s key witness, identifying Mr. Powell and Mr. Douglas as the shooters and State Trial Exhibit 2 as the car they drove. Over defense counsel’s objection, Miller elicited testimony from Smith that he had not “receive[d] any benefit, any sort of help on [Smith’s unlawful possession] case as a result of what happened to [him] in this case.” Powell Trial Tr. at 1066. Miller further elicited a denial from Smith that at no time during the pendency of the Douglas and Powell charges had Smith requested any help from Miller. During closing arguments, Miller argued Smith’s credibility in these terms: He came to court, he followed the law, he never tried to retaliate, he told what he knew, he told the truth. He went to prison on his own case and never asked for a thing .... He got a ten year to do [sic] sentence at 17 years of age for having some cocaine on him. He got whacked. And nobody interceded because he didn’t want it that way. Id. at 1612 (emphasis added). Mr. Powell was convicted on both counts. Upon the jury’s finding that he had knowingly created a great risk of death to more than one person, Mr. Powell was sentenced to death on the malice murder charge. He was sentenced to life imprisonment on the charge for shooting with intent to kill. On June 27, 1997, a little more than a month after Mr. Powell’s trial concluded, Warden Boone of ODOC’s Alford Correctional Center replied to a letter from Smith, stating that Miller had contacted Boone about merit days and lost credit days for application to Smith’s sentence. As Warden Boone had explained to Miller, he informed Smith that the “meritorious earned credit policy ... was not intended for a reward for testifying in felony cases,” so no merit days would be awarded to Smith. Evid. Hr’g Ex. 1C. At the same time, Warden Boone promised to give “serious consideration to the restoration of lost [earned] credits which would discharge [Smith’s] sentence.” Id. On July 24, Warden Boone approved the restoration of 400 days’ credit, effectively discharging Smith’s sentence. Smith was released by ODOC in August 1997. Subsequent Procedural History and Continuing Assistance to Smith Both Mr. Douglas and Mr. Powell appealed their convictions to the Oklahoma Court of Criminal Appeals (OCCA) and later pursued state collateral relief. In Douglas /, the OCCA affirmed Mr. Douglas’s direct appeal of his convictions and sentence in the face of some nineteen asserted propositions of error. 951 P.2d at 681. The asserted errors overlap with grounds Mr. Douglas would later assert in his federal habeas petition, including pros-ecutorial misconduct, ineffective assistance of counsel, and failure to instruct claims. See id. at 673v74 (prosecutorial misconduct), 678 (failure to instruct), 679-80 (ineffective assistance of counsel). Mr. Douglas raised an additional claim of cumulative error in the original application for postconviction relief that he filed in the OCCA while his direct appeal was still pending. Douglas II, 953 P.2d at 352-54. The OCCA rejected the claims Mr. Douglas raised in the state post-conviction collateral proceedings. Id. at 354. As with Mr. Douglas, the OCCA later rejected a broad range of claims asserted by Mr. Powell on direct appeal, although none of those claims are currently before this court. Powell I, 995 P.2d at 542. The OCCA likewise denied Mr. Powell’s application for postconviction relief in an unpublished opinion. Mr. Douglas filed his initial petition for a writ of habeas corpus pursuant to 28 U.S.C. § 2254 on August 2, 1999, raising ten grounds for relief including the failure to instruct, prosecutorial misconduct, cumulative error, and ineffective assistance of counsel. Douglas III (Ground D — failure to instruct); id. at 30-49 (Ground G— prosecutorial misconduct); id. at 53-54 (Ground J — cumulative error); id. at 54-66 (Ground B — ineffective assistance). The district court denied all relief on January 10, 2001. Notably, Mr. Douglas filed a timely Rule 59 motion for a new trial and a motion for time to submit affidavits regarding newly discovered evidence, but these motions were denied. Mr. Douglas then filed a notice of appeal and, simultaneously, motions in the district court for reconsideration and to hold the court’s decision in abeyance to allow exhaustion of new issues in state court. These motions were likewise denied on March 21, 2001. The district court then granted Mr. Douglas a certificate of appealability (COA). While Mr. Powell and Mr. Douglas sought relief from their convictions, Smith continued his criminal career and his contacts with Brad Miller, the prosecutor. In October 1997, Smith was arrested for the shooting of Joe Shells and was charged with assault with a deadly weapon in case No. CF-98-1545. Miller dismissed the case against Smith, citing insufficient evidence of identification. In February 1998, Smith committed a drive-by shooting, according to an information filed in case No. CF-98-1162, but Miller approved dropping the charges against Smith, purportedly due to lack of cooperation from the victims. In May 1999, Smith allegedly beat his girlfriend with a baseball bat and was charged in case No. CF-99-3338 with assault and battery with a dangerous weapon. On March 8, 2000, before his trial on the assault charge, Smith was again arrested, and charged in case No. CF-00-1683, this time for trafficking in crack cocaine. On March 16 of that year, even though he was no longer in the district attorney’s office, Miller contacted the assistant district attorney prosecuting Smith in the trafficking case to inform him that Smith had testified in the Douglas and Powell trials. While again in jail in July 2000, Smith was arrested on a Texas warrant for a June 2000 murder in Wichita Falls. After his conviction in the assault case in January 2001 yielded a fifteen-year sentence, Smith was offered a deal in March 2001 on the trafficking charge that resulted in a five-year sentence to run concurrently with his sentence for the assault. This unusually lenient sentence was a result of Miller’s call to the prosecuting district attorney. Evid. Hr’g Ex. 32 (affidavit of Smith’s counsel in trafficking case). Smith was indicted for the Texas murder charge in October 2001, pled guilty to a reduced aggravated robbery charge in December 2002, and received a twelve- and-a-half-year sentence concurrent with his Oklahoma sentences. Smith’s Recantation On May 17, 2001, four months after the district court denied Mr. Douglas’s initial habeas petition, Smith executed a handwritten affidavit recanting his identification of Yancy Douglas and Paris Powell as the shooters and asserting that he had received Miller’s assistance in exchange for his testimony, contrary to his denials at both trials. Specifically, Smith asserted that he told Miller he was unable to identify any of the shooters and that he would not testify against either Mr. Douglas or Mr. Powell unless Miller provided assistance on Smith’s then-pending trafficking case. Evid. Hr’g Ex. 4, at ¶ 4. Smith stated that, at his request, Miller contacted the parole board in 1995 and Warden Boone in 1997 to secure Smith’s release from prison. Miller’s assistance continued after the conclusion of both trials, according to Smith’s affidavit, including when Miller dismissed an assault charge against Smith in 1998 under the threat by Smith that he would reveal his perjury in the trials. Id. at 3. A week later, Smith executed a second affidavit containing the same allegations. Evid. Hr’g Ex. 1. Given this evidence, on October 29, 2001, Mr. Douglas filed a motion asking us to remand to the district court his pending appeal, docketed as case No. 01-6094. Alternatively, he sought permission to file a second habeas petition pursuant to 28 U.S.C. § 2244(b)(3)(A), asserting as grounds for relief claims stemming from Smith’s recantation and the suppression of impeachment evidence. We determined he had made a prima facie case that his application satisfied the prerequisites of § 2242(b)(2), and we granted him permission on December 12, 2001, to file a second habeas petition in the district court. We entered an order in No. 01-6094 abating proceedings in the appeal pending disposition by the district court of the second petition. Mr. Douglas filed the new habe-as petition on January 28, 2002. The district court abated proceedings on that petition on December 2, 2002, to permit Mr. Douglas to return to state court to exhaust new claims. Mr. Douglas filed an original application for postconviction relief in the OCCA on June 12, 2003. The OCCA denied relief on procedural grounds on August 7, 2003. In the meantime, Mr. Powell timely filed his initial petition for a writ of habeas corpus on September 20, 2001. His first two asserted grounds for relief were based on Smith’s recantation and allegations that Miller knowingly had suborned Smith’s perjury and suppressed impeaching evidence. Mr. Powell filed a motion seeking to excuse his failure to exhaust these claims or, alternatively, to abate proceedings pending state exhaustion. On December 2, 2002, the district court abated proceedings on Mr. Powell’s petition and ordered him to return to state court. Mr. Powell filed a second state application for postconviction relief, which the OCCA denied on procedural grounds on June 11, 2003. Even as Mr. Douglas and Mr. Powell filed their habeas petitions based on Smith’s recantation, however, further developments complicated the picture. On January 17, 2002, Smith executed a third affidavit repudiating his recantation and confirming the veracity of his trial testimony. But on May 16, 2002, Smith executed his fourth affidavit, recanting his repudiation of his recantation and claiming that his third affidavit had been executed at the direction of investigators from the Oklahoma State Bureau of Investigation (OSBI) under the threat of a perjury charge if he did not repudiate his earlier recantations. When Mr. Douglas’s habeas counsel learned about the OSBI investigation, he filed a joint application with Mr. Powell’s counsel in the district court for a protective order and discovery, alleging that witnesses in petitioners’ habeas proceedings were being threatened with prosecution for perjury. Subsequently, on March 26, 2004, counsel for Mr. Douglas and Mr. Powell obtained access for the first time to the Oklahoma County District Attorney’s files on the prosecutions and were finally provided documents that lent support to the factual allegations made by Smith in his recantation affidavits. Joint Evidentiary Hearing and District Court’s Decisions Upon requests from Mr. Douglas and Mr. Powell, the district court held a joint evidentiary hearing on questions raised by Smith’s recantation of his trial testimony. Although fifteen witnesses testified at the hearing, of particular importance to the district court was the testimony of Smith and Miller. Smith testified that everything in his first affidavit recanting his trial testimony was true, that he was unable to identify anyone in the car during the shooting because he was intoxicated by marijuana and alcohol and because of the lighting conditions, that his initial indications were prompted by the statements of someone else present at the scene of the shooting, and that he told Brad Miller he could not identify the assailants. Douglas IV at 9. Smith also testified that in his first meeting with Miller, Miller mentioned his pending trafficking charge and the crack cocaine Smith had been carrying at the scene of the shooting. Evid. Hr’g Tr., vol. I at 36-37. Smith said he told Miller he would not testify unless Miller helped him on his pending trafficking case. Douglas IV at 9; Evid. Hr’g Tr., vol. I at 37-38. Smith reaffirmed the falsity of his trial testimony identifying Mr. Powell and Mr. Douglas as the shooters and denying the existence of a deal between himself and the prosecution. Notably, Smith stated that prior to Mr. Douglas’s trial, he and Miller had discussed Smith’s hearing before the parole board and that Miller promised to help, but only after the trial in order to preserve Smith’s credibility. Evid. Hr’g Tr., vol. I at 49, 61. Miller also testified at the evidentiary hearing. He denied that Smith ever asked for his help prior to either trial or that there was a deal for Smith’s testimony. Evid. Hr’g Tr., vol. IV at 617-20, 627, 637. Miller stated that Smith initially did not want help because he did not want to be labeled a snitch. Id. at 614-15. Miller explained that his contact with the parole board after Mr. Douglas’s trial was motivated by Miller’s respect for Smith’s willingness to testify, not by a deal, and that Smith was unaware of Miller’s letter. Douglas IV at 10. Miller also opined that such assistance did not trigger his duty as a prosecutor to disclose exculpatory or impeaching evidence. Id. at 11. On January 31, 2006, the district court announced its decision with respect to Mr. Douglas. It found that the testimony at the evidentiary hearing of both Smith and Miller was not credible. It stated that no other evidence had been submitted “to contradict ... Smith’s testimony in [Mr. Douglas’s] trial denying the existence of any deals.” Id. at 18. Thus, the court held that Mr. Douglas had not “presented sufficient facts to raise a serious question about the use and suppression of false evidence by the State or regarding the existence of a deal [prior to Mr. Douglas’s trial] in exchange for ... Smith’s ... testimony.” Id. at 18, 21. Under the facts presented, the court held that there was “no reasonable probability of a different result, and that [Mr. Douglas’s] trial resulted in a verdict worthy of confidence.” Id. at 21. The court therefore denied Mr. Douglas’s petition on the merits. The court later granted a COA on the grounds raised in Mr. Douglas’s petition. The district court reached a different conclusion as to Mr. Powell. It found that the testimony at the evidentiary hearing of both Smith and Miller was “highly suspect.” Powell III at 20. Despite Smith’s repeated changes in testimony, the court determined that a “[r]eview of the facts convinces the Court that Derrick Smith’s testimony at [Mr. Powell’s] trial regarding no help or assistance with his ten-year sentence was false.” Id. at 20. The court found that Miller’s failure to correct these statements, his emphasis of the point in his own closing argument, and his failure to turn over to the defense his letter to the parole board and Smith’s letter to his mother all constituted violations of Brady v. Maryland, 373 U.S. 83, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963), and Giglio v. United States, 405 U.S. 150, 92 S.Ct. 763, 31 L.Ed.2d 104 (1972). Concluding that these violations rendered Mr. Powell’s verdict unworthy of confidence, the court conditionally granted his petition. It dismissed as moot, without prejudice, Mr. Powell’s other claims. The district court granted a COA permitting Mr. Powell to appeal the conditional nature of the writ granted him. The Appeals In Part II of this opinion, we address in general the applicable standards of review governing the various claims raised in these appeals. In Part III, we discuss Mr. Powell’s Brady and Giglio claims and Mr. Powell’s cross-appeal. We affirm the district court’s order granting a conditional writ of habeas corpus to Mr. Powell. In Part IV, we address Mr. Douglas’s petitions, which present a more complicated procedural challenge. We are persuaded that the unique circumstances of this case warrant treating Mr. Douglas’s Brady and Giglio claims as part of his initial habeas petition, specifically as a supplement to his prosecutorial misconduct claim involving vouching for the credibility of the eyewitness, Derrick Smith. On that basis, we reverse the district court’s denial of his habeas petitions. II Standards of Review The petitions here were filed after the effective date of the Antiterrorism and Effective Death Penalty Act of 1996 (AED-PA). Thus, our review of the claims in this appeal are governed by AEDPA’s standards to the extent that the claims were adjudicated on the merits by an Oklahoma state court. See Williams v. Taylor, 529 U.S. 420, 429, 120 S.Ct. 1479, 146 L.Ed.2d 435 (2000). We may grant habeas relief on such claims only if the state court’s decision “was contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court of the United States,” 28 U.S.C. § 2254(d)(1), or “was based on an unreasonable determination of the facts in light of the evidence presented in the State court proceeding,” § 2254(d)(2). We presume that the state court’s findings of fact are correct unless rebutted by the petitioner by clear and convincing evidence. See § 2254(e)(1). We review de novo a district court’s legal analysis of the state court’s merits decision. Bland v. Sirmons, 459 F.3d 999, 1009 (10th Cir.2006). A state court decision is contrary to clearly established federal law under section 2254(d)(1) “if the state court arrives at a conclusion opposite to that reached by [the Supreme Court] on a question of law or if the state court decides a case differently than [the Supreme Court] has on a set of materially indistinguishable facts.” Mitchell v. Gibson, 262 F.3d 1036, 1045 (10th Cir.2001) (quoting Williams, 529 U.S. at 412-13, 120 S.Ct. 1495). “It is not enough that the state court decided an issue contrary to a lower federal court’s conception of how the rule should be applied; the state court decision must be ‘diametrically different’ and ‘mutually opposed’ to the Supreme Court decision itself.” Bland, 459 F.3d at 1009 (quoting Williams, 529 U.S. at 406, 120 S.Ct. 1495). A state court decision is an unreasonable application of federal law under section 2254(d)(2) “if the state court identifies the correct governing legal principle from [the Supreme Court’s] decisions but unreasonably applies that principle to the facts of the prisoner’s ease.” Williams, 529 U.S. at 413, 120 S.Ct. 1495. The reasonableness of the state court’s application of federal law is to be evaluated by an objective standard. See id. at 409-10, 120 S.Ct. 1495. The Supreme Court has cautioned “that an unreasonable application of federal law is different from an incorrect or erroneous application of federal law.” Id. at 412, 120 S.Ct. 1495 (emphasis in original). Mitchell, 262 F.3d at 1045. The deferential AEDPA standards of review do not apply “if the state court employed the wrong legal standard in deciding the merits of the federal issue.” Cargle v. Mullin, 317 F.3d 1196, 1202 (10th Cir.2003). In addition, the § 2254(d) standards “do[ ] not apply to issues not decided on the merits by the state court.” Bland, 459 F.3d at 1010. For claims that the state court did not address on the merits, we review legal conclusions of the district court de novo. Id. If the district court held an evidentiary hearing pursuant to 28 U.S.C. § 2254(e), as here, we review its factual findings for clear error; if it “based its factual findings entirely on the state court record, we review that record independently.” Id. As we discuss further in fra, when a state court applies plain error review in disposing of a federal claim, the decision is on the merits to the extent that the state court finds the claim lacks merit under federal law. Cargle, 317 F.3d at 1206. Where a state court denies relief “for what it recognizes or assumes to be federal error, because of the petitioner’s failure to satisfy some independent state law predicate,” the decision is not on the merits and, assuming an excuse to procedural bar, “the federal court would be left to resolve the substantive claim de novo, unconstrained by § 2254(d).” Id. Even where we determine ah error occurred that might establish relief under these standards of review, “[u]nless the error is a structural defect in the trial that defies harmless-error analysis, we must apply the harmless-error standard” enunciated in Brecht v. Abrahamson, 507 U.S. 619, 113 S.Ct. 1710, 123 L.Ed.2d 353 (1993), which holds that “habeas relief is proper only if the error had a ‘substantial and injurious effect or influence in determining the jury’s verdict.’ ” Bland, 459 F.3d at 1009 (quoting Brecht, 507 U.S. at 623, 113 S.Ct. 1710). A “substantial and injurious effect” exists when the court holds at least a “grave doubt” about the effect of the error on the jury’s verdict. See O’Neal v. McAninch, 513 U.S. 432, 436, 115 S.Ct. 992, 130 L.Ed.2d 947 (1995). Grave doubt exists when, “in the judge’s mind, the matter is so evenly balanced that he feels himself in virtual equipoise as to the harmlessness of the error.” Id. at 435, 115 S.Ct. 992. Because procedural posture determines our standard of review under AEDPA, which, in turn, is often determinative in habeas cases like this one, a brief recap of the current posture of Mr. Powell’s and Mr. Douglas’s claims is appropriate. Our review of Mr. Douglas’s initial habeas claims are governed by the standards set forth previously. Review of both petitioners’ Brady claims is more complicated. Neither Mr. Powell nor Mr. Douglas raised a Brady claim in either of their direct appeals or in their initial applications for state postconviction collateral review. The facts underlying the claims came to light before Mr. Powell filed his federal habeas petition, but only after the district court entered its decision on Mr. Douglas’s federal habeas petition and his appeal was pending before us. Although Mr. Powell was able to include the Brady claim in his habeas petition, it was necessary for Mr. Douglas to request permission from us to file an additional petition to include his similar Brady claim because the claim was unavailable to him earlier through no fault of his own, as we discuss infra. As we also discuss infra, we have concluded that because of the unique circumstances of this case, Mr. Douglas’s Brady claim is more appropriately characterized as a supplement to his initial claims of prosecutorial misconduct, and we address it accordingly. With respect to the Brady claims, the district court stayed its proceedings on the respective pending petitions to permit Mr. Douglas and Mr. Powell to file second applications for state postconviction collateral relief to exhaust their claims. The OCCA denied both applications on strictly procedural grounds, holding that the claims were barred by Rule 9.7(G)(3), Rules of the Court of Criminal Appeals, 22 Oicla. Stat. Ch. 18, app. (2003), which requires successive postconviction petitions to be filed “sixty (60) days from the date the previously unavailable legal or factual basis serving as the basis of the claim for the new issue is ... discovered.” The district court determined that the State’s-procedural bar was inadequate to prevent its review because the bar had not been evenhandedly applied to similar claims. Douglas IV, Dkt. No. 86, filed October 4, 2004. The court subsequently held a joint evidentiary hearing on both Mr. Powell’s and Mr. Douglas’s similar Brady claims. As noted above, it denied relief to Mr. Douglas and conditionally granted relief to Mr. Powell. The State does not include in its appeal of the district court’s grant of the writ to Mr. Powell, nor in its response to Mr. Douglas’s appeal, any argument that the district court erred in finding the state procedural bar inadequate or in granting the evidentiary hearing. Accordingly, given that the state court never addressed the Brady claims on the merits, we owe it no AEDPA deference. Because the district court held an evidentiary hearing, we review the district court’s legal conclusions on the Brady claims de novo and its factual findings for clear error. See Bland, 459 F.3d at 1010. When we are not bound by AED-PA deference, we review de novo the existence of a Brady violation. Foster v. Ward, 182 F.3d 1177, 1192 (10th Cir.1999). The subsidiary question of whether suppressed evidence is material is a mixed question of law and fact which we also review de novo. United States v. Trujillo, 136 F.3d 1388, 1393 (10th Cir.1998). We review for clear error the district court’s factual finding that Smith’s’ testimony at Mr. Powell’s trial regarding the lack of a deal with the prosecutor was false. See Romano v. Gibson, 239 F.3d 1156, 1175 (10th Cir.2001). We review de novo the court’s determination that Mr. Douglas’s evidence was insufficient to support the same conclusion. See United States v. Chavis, 461 F.3d 1201, 1207 (10th Cir.2006) (“Sufficiency of the evidence is a question of law that we review de novo....”). Applying these standards, we turn to an assessment of the claims raised in these two appeals. Because of their different procedural postures, we treat Mr. Powell’s appeal separately from Mr. Douglas’s appeal. Ill Mr, Powell’s Napue/BradylGiglio Violations Beginning with its seminal decisions in Napue v. Illinois, 360 U.S. 264, 79 S.Ct. 1173, 3 L.Ed.2d 1217 (1959), and Brady v. Maryland, 373 U.S. 83, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963), the Supreme Court established the principle that criminal convictions obtained by presentation of known false evidence or by suppression of exculpatory or impeaching evidence violates the due process guarantees of the Fourteenth Amendment. “[Djeliberate deception of a court and jurors by the presentation of known false evidence is incompatible with rudimentary demands of justice.” Giglio v. United States, 405 U.S. 150, 153, 92 S.Ct. 763, 31 L.Ed.2d 104 (1972) (internal quotations omitted). “The same result obtains when the State, although not soliciting false evidence, allows it to go uncorrected when it appears.” Napue, 360 U.S. at 269, 79 S.Ct. 1173. The government’s obligation to disclose exculpatory evidence does not turn on an accused’s request. Strickler v. Greene, 527 U.S. 263, 280, 119 S.Ct. 1936, 144 L.Ed.2d 286 (1999). “In order to comply with Brady, ... the individual prosecution has a duty to learn of any favorable evidence known to the others acting on the government’s behalf.” Id. at 281, 119 S.Ct. 1936 (quotation marks omitted). Under this framework, no distinction is recognized between evidence that exculpates a defendant and “evidence that the defense might have used to impeach the [State’s] witnesses by showing bias and interest.” United States v. Bagley, 473 U.S. 667, 676, 105 S.Ct. 3375, 87 L.Ed.2d 481 (1985). We emphasize that the duty to disclose such information continues throughout the judicial process. Smith v. Roberts, 115 F.3d 818, 820 (10th Cir.1997). A Brady violation has three essential elements: “[t]he evidence at issue must be favorable to the accused, either because it is exculpatory, or because it is impeaching; that evidence must have been suppressed by the State, either willfully or inadvertently; and prejudice must have ensued.” Banks v. Dretke, 540 U.S. 668, 691, 124 S.Ct. 1256, 157 L.Ed.2d 1166 (2004) (quoting Strickler, 527 U.S. at 281-82, 119 S.Ct. 1936 (1999)). Prejudice satisfying the third element exists “when the suppressed evidence is material for Brady purposes.” Id. (internal quotations omitted). Favorable evidence “is material ... ‘if there is a reasonable probability that, had the evidence been disclosed to the defense, the result of the proceeding would have been different.’” Kyles v. Whitley, 514 U.S. 419, 433, 115 S.Ct. 1555, 131 L.Ed.2d 490 (1995) (quoting Bagley, 473 U.S. at 682, 105 S.Ct. 3375). As the Court has noted, this is not a requirement that the evidence be sufficiently strong to ensure an acquittal had it been presented at trial: The question is not whether the defendant would more likely than not have received a different verdict with the evidence, but whether in its absence he received a fair trial, understood as a trial resulting in a verdict worthy of confidence. A “reasonable probability” of a different result is accordingly shown when the government’s evidentiary suppression “undermines confidence in the outcome of the trial.” Id. at 434, 115 S.Ct. 1555 (quoting Bagley, 473 U.S. at 678, 105 S.Ct. 3375). Nor is the materiality requirement a sufficiency of the evidence test: A defendant need not demonstrate that after discounting the inculpatory evidence in light of the undisclosed evidence, there would not have been enough left to convict.... One does not show a Brady violation by demonstrating that some of the inculpatory evidence should have been excluded, but by showing that the favorable evidence could reasonably be taken to put the whole case in such a different light as to undermine confidence in the verdict. Id. at 434-35. The petitioner “bears the burden of presenting evidence to establish a Brady or Giglio violation.” Foster, 182 F.3d at 1191. However, once Brady error is established under the Kyles materiality standard, “there is no need for further harmless-error review.” Kyles, 514 U.S. at 435, 115 S.Ct. 1555. This is because a reasonable probability of a different result in the proceeding “necessarily entails the conclusion that the suppression must have had ‘substantial and injurious effect or influence in determining the jury’s verdict.’ ” Id. (quoting Brecht, 507 U.S. at 623, 113 S.Ct. 1710). On appeal, the State contends the district court erred in granting habeas relief to Mr. Powell on the Brady claims because it failed to give proper consideration to the evidence in calculating whether the suppressed and false evidence was material. Mr. Powell cross appeals, contending the district court erred in refusing to grant his writ unconditionally. A. Merits At Mr. Powell’s trial, Derrick Smith’s testimony played the indispensable role of identifying Mr. Douglas and Mr. Powell as the gunmen, thereby providing the only direct evidence linking them to the murder of Shauna Farrow and the shooting of Smith. Having reviewed the entire state trial record, we agree with the district court’s characterization of Smith’s testimony as “the linchpin to a conviction.” Powell III at 23. Had the jury discounted Smith’s testimony as not credible, it almost certainly would not have had sufficient evidence on which to convict. Smith’s credibility, and Mr. Powell’s inability to impeach him by presenting evidence of his expectation of a benefit in exchange for his testimony, thus played a critical role in determining the verdict. As the Supreme Court stated in originating the Brady line of cases, “[t]he jury’s estimate of the truthfulness and reliability of a given witness may well be determinative of guilt or innocence, and it is upon such subtle factors as the possible interest of the witness in testifying falsely that a defendant’s life or liberty may depend.” Napue, 360 U.S. at 269, 79 S.Ct. 1173. The standard of materiality for Brady claims such as those presented here “is met when ‘the favorable evidence could reasonably be taken to put the whole case in such a different light as to undermine confidence in the verdict.’ ” Banks, 540 U.S. at 698, 124 S.Ct. 1256 (quoting Kyles, 514 U.S. at 435, 115 S.Ct. 1555). “In short, [the petitioner] must show a ‘reasonable probability of a different result.’ ” Id. (quoting Kyles, 514 U.S. at 434, 115 S.Ct. 1555). We have discarded as immaterial under this standard undisclosed impeachment evidence where it was cumulative of evidence of bias or partiality already presented “and thus would have provided only marginal additional support for [the] defense.” Trujillo, 136 F.3d at 1394. In contrast, we have upheld the materiality of nonduplicative impeachment evidence where the witness provided the sole evidence linking the petitioner to the crime. See Nuckols v. Gibson, 233 F.3d 1261, 1266 (10th Cir.2000). Read together, these cases support the principle that evidence insignificantly impacting the degree of impeachment may not be sufficient to meet the Kyles materiality standard, while evidence significantly enhancing the quality of the impeachment evidence usually will. The evidence suppressed here falls into the latter category. In Nuckols, the admissibility of the only evidence linking the petitioner to the crime hinged on the testimony of a single witness, the deputy sheriff, Ware, to whom Nuckols confessed after initially invoking his Miranda rights. Id. at 1263-64. [I]t was critical for the State to establish the admissibility of that confession, but its admissibility hinged upon proof that Mr. Nuckols initiated the interview which produced the incriminating statements.... The only witnesses on this critical point were Ware and [Nuckols], each of whom negated the other’s testimony. If Ware’s testimony that Mr. Nuckols initiated the interrogation were impeached, the entire support for the State’s case would have been significantly undermined, if not destroyed altogether. Id. at 1266. The State failed to disclose facts about Ware which would have “provided the defense with the opportunity to call into question whether Ware had a motive for his testimony” or “whether Ware had a motive to goad Nuckols into waiving his right to counsel during the interrogation and confessing to the crime.” Id. at 1267. Although we did no more than suggest the possibility for the sake of argument that Ware had ulterior motives, we still concluded that the denied opportunity to cross-examine him on these points due to the State’s suppression of evidence raised a reasonable probability of a different result sufficient to undermine confidence in the verdict: Id. The parallel between Nuckols and the Powell trial is clear. Like Ware, Smith was an indispensable witness for the State’s case against Mr. Powell. And although Mr. Powell’s counsel attempted to impeach Smith on the issue of his motive to testify, he was stonewalled by Smith’s repeated denials of the existence of a deal, ánd stymied from rebutting those denials by the State’s failure to produce relevant impeaching evidence. This combination was as effective at deflecting counsel’s attempts at impeachment as was the court order in Nuckols excluding counsel’s attempts to raise Ware’s motives. Id. at 1265. Given the paramount importance of Smith to the State’s case, we agree with the district court’s conclusion that there is a reasonable probability the result of Mr. Powell’s trial would have been different if the defense had had the ability to impeach Smith with evidence of the deal the prosecution made in exchange for his testimony. Relying on Mataya v. Kingston, 371 F.3d 353 (7th Cir.2004), the State contends Smith’s earliest identification of Mr. Douglas and Mr. Powell as the gunmen was somehow “self-validating.” But the facts in Mataya are not comparable to this case. There the witness, whose deal with the prosecution was not disclosed, revealed details about the crime that he could not have known unless they had been revealed to him by the murderer. Id. at 357. Hence, his testimony that Mataya had confessed to him was validated by the details he knew. Here, Smith’s identification of Mr. Powell as the shooter was not verifiable in the same fashion. The more accurate characterization of Smith’s statement is that it was somewhat corroborated, not that it was self-validating. That one of Smith’s several contradictory post-shooting statements was corroborated by other evidence is not an especially strong argument on this record, where Smith was the only eyewitness to the shooting and there was no other direct evidence connecting Mr. Powell to the crime. As in Nuckols, 233 F.3d at 1267, the State offers contentions that should have been resolved by a jury but were not because the prosecution withheld or concealed crucial impeachment evidence. Because impeachment of the witness who held the key to the successful prosecution of Mr. Powell was denied to the defense, the district court correctly concluded that the State’s Brady violations were material. In so deciding, the court found that, “at a minimum, Mr. Smith used his identification testimony in an effort to benefit himself, Mr. Miller was aware of Mr. Smith’s requests for assistance, had acted on his request, and that this information was not known by or conveyed to [Mr. Powell’s] trial counsel.” Powell III at 21-22. Under these facts and in light of the necessity of the jury believing Smith’s testimony to support a verdict of guilty, we agree with the district court that Mr. Powell’s trial did not yield a verdict worthy of confidence. Accordingly, the district court correctly granted Mr. Powell’s petition for a writ of habeas corpus. B. Conditional Writ In his cross-appeal, Mr. Powell contends the district court should have granted the writ with an unconditional directive releasing him from prison and barring a retrial. We review the district court’s formulation of an appropriate habeas corpus remedy for abuse of discretion. See Paxton v. Ward, 199 F.3d 1197, 1219 (10th Cir.1999). A federal writ of habeas corpus “does not generally bar a retrial of the petitioner on the charges underlying his defective conviction.” Capps v. Sullivan, 13 F.3d 350, 352 (10th Cir.1993). “In fact, rather than barring a new trial, the district court normally should facilitate it by suspending the writ for a time reasonably calculated to provide the state an adequate opportunity to conduct the new trial.” Id. Nevertheless, “[i]n issuing a writ of habeas corpus, a federal court has the power and authority to dispose of habeas corpus matters as law and justice require.” Paxton, 199 F.3d at 1219 (internal quotation and citation omitted). The statutory basis for the federal courts’ authority to render ha-beas corpus relief, 28 U.S.C. § 2243, “vests the federal courts with ‘the largest power to control and direct the form of judgment to be entered in cases brought ... on habeas corpus.’ ” Capps, 13 F.3d at 352 (quoting Hilton v. Braunskill, 481 U.S. 770, 775, 107 S.Ct. 2113, 95 L.Ed.2d 724 (1987)) (alteration in original). Barring a new trial may be necessary, for instance, “when the error forming the basis for the relief cannot be corrected in further proceedings,” and it may be a permissible form of relief when “other exceptional circumstances exist such that the holding of a new trial would be unjust.” Id. at 352, 353. The classic example of such an irremediable error, necessitating the grant of an unconditional writ, is “when a[new] trial would violate the Double Jeopardy Clause of the Fifth Amendment.” Id. at 352. But where nothing in the record suggests that the constitutional violation on which habeas corpus relief is predicated could not be redressed by holding a retrial, granting an unconditional writ constitutes an abuse of discretion. See id. at 353. Nothing in the record of Mr. Powell’s trial indicates irremediable error, and he suggests none, arguing only that the duration of the State’s continuing Brady violations rises to the level of extraordinary circumstances justifying an unconditional writ. Without speculating as to whether granting an unconditional writ would be an abuse of discretion under these circumstances, it is plain that granting a conditional writ is not. IY Mr. Douglas’s Due Process Claims Mr. Douglas contends we should overturn his convictions because the prosecutor violated his due process right to a fair trial by vouching for the credibility of Smith, the lynchpin witness, by knowingly eliciting false testimony from Smith to bolster his credibility, by failing to correct testimony he knew to be false, and by failing to disclose that Smith was testifying against Mr. Douglas pursuant to an agreement by the prosecutor to assist Smith in extracting him from numerous ongoing and potential legal difficulties. In addressing these arguments, we also determine the standard of review applicable to each. A. Prosecutorial Misconduct “Inappropriate prosecutorial comments, standing alone, would not justify a reviewing court to reverse a criminal conviction obtained in an otherwise fair proceeding.” United States v. Young, 470 U.S. 1, 11, 105 S.Ct. 1038, 84 L.Ed.2d 1 (1985). But habeas relief is appropriate when a prosecutor’s comments “so infected the trial with unfairness as to make the resulting conviction a denial of due process.” Donnelly v. DeChristoforo, 416 U.S. 637, 643, 94 S.Ct. 1868, 40 L.Ed.2d 431 (1974). If an improper comment implicates “specific guarantees of the Bill of Rights,” federal courts “ha[ve] taken special care to assure that prosecutorial conduct in no way impermissibly infringes them.” Id. When analyzing prosecutorial misconduct claims, we have rejected prior invitations “to parse the prosecutor’s argument word by word in a vacuum.” Paxton, 199 F.3d at 1217. Rather, we have stated that [i]nquiry into fundamental fairness requires examination of the entire proce