"all visible gunfire and shrapnel damage was caused by bullets entering from immediately behind the bomber" not from the right. Subsequently, Barber petitioned the Air Force Board for Correction of Military Records to have his half credit on the bomber shared with Lanphier changed to a whole credit. In September 1991, the Air Force History Office advised the board that "enough uncertainty" existed in both Lanphier's and Barber's claims for them both to be accepted; the board's decision was split on Barber's petition. Secretary of the Air Force Donald Rice ruled to retain the shared credit. Barber then applied to the U.S. 9th Circuit Court of Appeals to have the ruling of the Secretary of the Air Force overturned and the opposing claims re-investigated, but the court refused to intervene. In May 2006, Air Force Magazine published a letter by Doug Canning, a former pilot of the 347th Fighter Group who flew on Operation Vengeance (he escorted Lieutenant Holmes back to the Russell Islands). Canning, who was friends with both Lanphier and Barber, stated that Lanphier had written the official report, medal citations, and several magazine articles about the mission. He also claimed Barber had been willing to share the half credit for shooting down Yamamoto until Lanphier had given him an unpublished manuscript he had written claiming he alone had shot down the admiral. Canning agreed that Barber had a strong case for his claim citing the testimony of another pilot from Yamamoto's Zero escort, Kenji Yanagiya, who saw Yamamoto's "Betty" crash 20 to 30 seconds after being hit from behind by fire from a P-38. Likewise, the second Betty carrying Ugaki crashed 20 seconds after being struck by aircraft fire. Canning stated categorically that the P-38Gs flown that day did not have aileron boost to assist in turning (as did later models) making it physically impossible for Lanphier's aircraft to have made the 180 degree turn fast enough to intercept Yamamoto's plane in less than 30 seconds. The Air Force later disqualified Lanphier's claim for shooting down a Zero in the battle, meaning that Lanphier lost his "ace" status as his total number of air-to-air kills dropped from five to four. In spite of criticism from Barber and other surviving pilots from the mission, Lanphier continued to claim credit for downing Yamamoto until his death in 1987. Most newspaper obituaries reporting Lanphier's death credited him with killing Yamamoto.