I don't see how this is more confirmation of Sherry's work. Many folks have posited that a shooter was on the South Knoll, including my pal Yellowbirch, but only Sherry has placed the entrance wound correctly based on scientific fact. Read the book and you may come to understand that much better and realize that just saying it was a frontal shot is not support because when you base your claim on bogus evidence one tends to dismiss it. Obviously, as you've pointed out, TLR, in 2008 this fellow proved that he actually had no clue.
I base my statements on his premise that the entrance wound was in the left temple and brain matter was expelled from the right rear and going forward. IMO, this is just a guess due to the lack of knowledge about back spatter which actually came from an entrance wound in the upper right front quadrant of the skull. He is suggesting that the shot came from the president's left when it actually came from an area that was more straight ahead due to the position of the limo facing the South Knoll. Just think, as I've stated before, the bullet whizzed right past Mrs. Kennedy's head as she was leaning in so, if you based a trajectory on a left temple entrance and an exit from the right rear, there would be a high probability of it striking her and not the president.