Absolutely. Also the ambulance driver, Aubrey Rike, who described what he felt when he put his hand under JFK's head to do the standard lift to transfer a body from one stretcher to another.
The idea that the President's head would have flown backward from a shot that impacted the back of his head is preposterous.
I'm by no means a gunshot expert, but the impact of the bullet to the front of JFK's head is so violent, with brain matter exploding backward and upward, that to my semi-trained eye (I'm an engineer who started out as a physics major, and I do image analysis every day for my work) looks like it could have been an explosive projectile, just as the associate of Lucien Sarti stated.
You are quite likely a very good engineer and may have done well in physics, but some of us experienced in war time scenarios might disagree with you with regards to how a human body reacts when shot.
Enough said.