From the testimony/accounts of the Connallys (WC testimony):
John Connally: "I heard it [the shot] hit. It was a very loud noise, just that audible, very clear.
Immediately I could see on my clothes, my clothing, I could see on the interior of the car which, as I recall, was a pale blue, brain tissue, which I immediately recognized, and I recall very well, on my trousers there was one chunk of brain tissue as big as almost my thumb, thumbnail, and again I did not see the President at any time either after the first, second, or third shots, but I assumed always that it was he who was hit and no one else.
I immediately, when I was hit, I said, "Oh, no, no, no." And then I said, "My God, they are going to kill us all." Nellie, when she pulled me over into her lap----
Nellie Connally: "The third shot that I heard I felt, it felt like spent buckshot falling all over us, and then, of course, I too could see that it was the matter, brain tissue, or whatever, just human matter, all over the car and both of us."
If the bullet exited the rear of the head - and blew a hole out of it - then how did all of this material - brain tissue, blood - land
immediately in front of where JFK was? It landed on the Connallys - who said they felt it and saw it - and all inside the interior of the car in front of where JFK was sitting.
How is it possible for a bullet to blow out the back of JFK's head and have material exit from there (from where else could it exit?) and land
in front of him, in front of this back of the head blow out? The wind blew it? But they were headed into a wind, you can see the flags flying on the limo.
The Parkland doctors - those who said it appeared to be in the occipital region - were simply wrong about the location.
And for what it's worth, Robert McClelland was interviewed shortly after the assassination by a medical journal called The Texas State Journal of Medicine. He told them this about the location of the wound.
The wound was on the "right side of the head." Nothing about the back of it.
Full account of his and the other doctors is here:
https://texashistory.unt.edu/ark:/67531/metapth599863/m1/106/?q=Perry