The aircraft Jeff died in was heavily modified at the request of the owner, Bruce Pruett. The Prestone radiators had been replaced (no notation about the CG change was made) and the entire fuel system was modified, including the fuel selection switches, which were pinned. According to people who would know, the fire may have started pre-crash, not post crash, and the fuel selector switches may actually have just been in the position where Jeff left them when he stopped trying to get fuel to the engine and started trying to recover the aircraft. It was apparently his first or second flight in that plane, he had flown the other P-38, which had the original radiators and fuel system.
No doubt, Jeff was at fault, for allowing himself to end up in that position. However, it should be understood that he was in a modified aircraft, in a dangerous situation, with very little seat time in that particular aircraft.
The whole thing is a damned shame, Jeff was a good guy, both he and the plane were irreplaceable.