This CT legend began with a simple presentation (above) by the HSCA. The wounds through the neck were established using Clyde Snow's anatomical-positioning method; the center profile among the three head outlines seem to be the nearest to Snow's anatomical-position. Baden showed the transit angle changed as the torso changed, settling on the rightmost outline as the wounding position ("the position of the President at the time the missile struck.")
This "wounding position" is shown in the sketch on the left side of JFK F-46. Unfortunately the artist didn't re-orientate the head to vertical, and so a new legend grew out of this, that the HSCA neck transit could only work if the head was tilted forward as shown by the sketch.
The HSCA must have thought readers would be smart enough to realize that when the torso angle at "wounding position" was established then it followed that the head would have to be vertical as in life. But I've seen some doctors on the CT side who couldn't get this.
The HSCA clearly thought the head was at vertical and the neck transit was downward during the wounding. They portrayed it as such in a trajectory drawing.
Uhh, no. The HSCA Forensic Pathology Panel was at cross-purposes with its trajectory expert.
The FPP concluded the bullet rose within Kennedy's body, but that he was leaning sharply forward when struck. Their exhibits depict this lean.
Blakey went behind their backs and hired a trajectory expert, however. He even gave this expert, Thomas Canning, the authority to move the wounds if he wanted to. So he did.
As a consequence, Canning's exhibits show a bullet impacting at the base of the neck, two inches higher than the Pathology Panel placed the wound. Canning also made up some mumbo-jumbo about Kennedy leaning forward when shot in the back, and then sitting up in his seat before getting shot in the head. This was to hide that neither of the trajectories proposed by the HSCA (back to throat at 190, and cowlick to coronal suture at 313) made any sense when one studied the Zapruder film.
This, to me, was an absolute disgrace... And yes, I talked to Blakey about this at the 2014 Bethesda conference. He feigned interest and gave me his email address. But never responded.