While it's true that the simple momentum of a bullet will tend to push the target in the direction of its motion (although nowhere near as much as most people -- or Hollywood -- imagine, since the bullet may be fast, but it's quite light in comparison to the body it strikes), and while it's true that matter ejected from the site of the exit wound can also propel the body *backwards* towards the direction of the shot, both of these are minor compared to the larger issue.
The larger issue is that when the brain gets destroyed by massive trauma, the body will jerk in a *completely unpredictable* manner due to the effect of the trauma on the remaining brain/spinal/nerve tissues. The direction of JFK's motion after the head shot is almost surely determined primarily by reflexive spasmodic jerking of the body due to the destruction of much of the brain, and as such nothing can be drawn about the angle of the shot from the subsequent motion of the body.
Also note that when you watch the Zapruder film, there seems to be a short but noticeable delay between the moment of the "blood spray" and the moment the head/body begins to actually move backwards, constent with a reflex action and not consistent with imparted momentum (which is imparted instantaneously).
Sorry, but that is incorrect. In the kinematic mechanism of trauma, it is the square of the velocity that is significant not the mass of the projectile.
The direction of JFK's motion after the head shot is almost surely determined primarily by reflexive spasmodic jerking of the body due to the destruction of much of the brain, and as such nothing can be drawn about the angle of the shot from the subsequent motion of the body.
This explanation was refuted during the Warren inquiry itself. There can be some seizing after the shot, rarely tgat great - but never such that it would interfere with drawing conclusions about where the shots came form when analyzing body motion afterwards. Forensic pathology does exactly that - looks at bullet wounds, body motion if available, and position of the body after the shot to determine where the shot originated.
The idea that this 'neuromuscular event' would overcome the momentum of a bullet shot has long been held as one of the silliest things to come from the Warren commission.
What are your thoughts on the video of the Vietnamese General shooting the captured Vietnamese in the side of the head with a hand gun (lower velocity)-- shown on tv several times.
The victim's head moves in the direction of the bullet - I don't recall a snapback in the opposite direction of the bullet.