It appears to me that the damage was done to the " TOP " of the skull, which extended across to the right side, just above the ear.
Yes, which is why some of the material blew/exploded upwards and forward. The Connallys said that brain matter and blood landed on them. Greer and Kellerman said the same thing. And blood/brain matter landed on the front of the limo, on the hood. If the shot exited the back of the head how did all of that material land in front of JFK?
Interesting that, if I read their accounts properly, none of the ER doctors at Parkland said they saw that skin flap. I'll guess that Mrs. Kennedy flattened it out when she held JFK's head and it ended up covering much of the top/side wound. The doctors, not seeing the full extent of the wound, thought it was further back. Okay, that's a complete guess.
But I'm getting away from the OP and should sit this one out. Again, that GIF is amazing. And horrifying.