As I said, Mrs. Kennedy put the large flap of skull and skin back in place as best she could on the ride to Parkland. The doctors there saw him in that condition in fact, approximately in the condition shown in the above photo. They were also both in shock and trying to save the man's life, although it was futile. Once the president was pronounced dead, all examination stopped. So it is understandable that what they saw was the missing area of skull at the left-most meaning rear-most portion of the wound. By the way, the throat wound was a small exit wound. The doctors enlarged it when they did a tracheotomy.