Originally Posted by sailingfun

There are several good stills shots and movies that show what perhaps happened. It appears the trim tab came off the elevator. You can see it separate in one video and the aircraft pitches up instantly. This is a common problem in the P51 at high speeds and has happened before. It happened at Reno a few years back and the aircraft did a 9 g pitch up. The pilot in that case was able to recover the aircraft after it slowed and land.
In this case it appears the pitch up may have GLOC the 80 year old pilot. You can see in a close up still that he is slumped over out of sight in the cockpit just before impact.
The entire accident is very sad and perhaps had a better trim tab been mandated for 51's in air races it could have been avoided since its a known problem.