Creative Speculation

Kennedy's throat wound was an exit wound; the bullet passed through his shirt collar, which was compressing the skin of the neck. The ballistics assertions made there are also deeply flawed (as it's been shown that a 6.5mm Carcano possesses the ballistic characteristics and velocity to cause wounds similar to those observed in Kennedy and Connally).

http://mcadams.posc.mu.edu/factoid5.htm