[Larry]

Was the pilot found in the wreckage or was he found somewhere else as if he had been blown out of the aircraft in an explosion and or fell to his death?

If he was found in the wreck perhaps he could not reach it and put it on correctly in time or someone else took it and bailed out! My father knew of a case just post war when a crewmember snatched the first parachute available and bailed out of a doomed Wellington leaving others to die!

Another possibility is that the crew failed to load the correct number of chutes. Again I know of instances where other safety gear was left at base by mistake such as the dingy in the wing of a Wellington, which was doing a long over sea mission!