It's hardly surprising no-one, especially the Tinfoil Brigade, wants to touch this as the initial head movement at the moment of impact is forward and can only reasonably be explained by a shot from behind.
Just as important is the fact there is no "blowout" at the back of JFK's head shown in the Z-film but this is brushed off as an alteration to the film as if this was no big deal, as if there was plenty of time to make such a sophisticated alteration. There was no alteration to the film.
This Gif, created by John Mytton I believe, also demonstrates there was no blowout at the back of the head:
Of course, all the autopsy photos/x-rays were faked as well.
Try to imagine the thousands of papers, articles, books etc., written specifically to demonstrate this fakery.
It is my contention that all this wasted effort has emanated from a misunderstanding of the "back and to the left" motion.