"The Army film taken in 1948 of the goat shooting episodes convincingly explained the rearward reaction of the president's head as seen in the Zapruder film and very convincingly demonstrates that it could not have been caused by the frontal impact of a bullet, and equally convincingly demonstrates that it was caused by the convulsion of upper dorsal musculature receiving false signals from an exploding brain."
https://www.archives.gov/research/jfk/select-committee-report/part-4.html
Charles Petty, from the HSCA.
That was a statement of the HSCA committee. Petty does not refer to the sheep film. Has anyone actually seen the film and, if so, can someone provide a link?
I note that Petty made two serious errors, in my view (none of which relate the motion of JFK after the head shot).
First of all, to the question posed by Mr. Bugliosi at 4:15 about a 1 second delay of Connally after being struck in the back, Petty suggests that can occur because people react differently and people sometimes don't even know they have been struck. Obviously, that does not fit Connally's evidence, which was that he felt the impact and that that forceful impact like a punch to the back occurred after he had heard the first shot, recognized it as a rifle shot and, fearing an assassination attempt, had turned around to check on JFK.
The second error, at 5:50 where he says that the bullet never penetrated the rib bone or the radius bone. I am not sure how he concludes that it did not penetrate the rib. While it "circled around the outside of the chest" (4:00) initially, it blasted through the last 10 cm of rib. The bullet also caused a comminuted fracture of the radius. While I agree that this does not require penetrating the wrist if it merely deflected on impact, the SBT says that it penetrated the radius in order to enter the left thigh.