Since the question of helmets - or lack of them - has been raised in this investigation, perhaps there is another element that needs to be addressed. Shoulder harnesses and life jackets. There is a tendency for the shoulder straps to slide off to the side of the life jackets. With reports that both pilots struck their heads on the instrument panel, it is a distinct possibility that the shoulder harnesses were not effective.
I find the 92's shoulder harnesses occasionally need adjusting and the C+'s harnesses almost useless unless you cross the straps when you buckle in.