There usually isn't unless there's a running video camera. But I would say the investigators provided a pretty sound estimate.

From the report:
"The pilot's broken right wrist and the bent V brace suggest that the pilot was bracing or trying to resist a force imposed from behind. The broken ankles of the passenger behind the pilot are consistent with that person bracing with both feet, or pushing forward with both feet, at the time of impact. It is possible the passenger seated behind the pilot kicked the pilot's seatback forward and held it there, pushing the pilot into the instrument panel and the controls forward thereby inducing a dive."

Drunks are drunks. They're stupid beyond all comprehension. They killed almost 11,000 people in cars last year, and I doubt that they suspend their idiocies while in the air.

Art's suggestion that drunks "be hog tied, or stuffed in a sack, and carried as cargo. Perhaps lashed to one of the floats" certainly works for me. And in cars, buses, and trains, too.

Sue