The illustration in this article makes the same mistake as Oliver Stone did in the movie JFK where he positioned two chairs AT THE SAME HEIGHT to suggest only a "magic bullet" could have passed through Kennedy's neck and also struck Connolly in the back.
In fact, the middle seat in which Connolly was sitting was LOWER than the back seat in which Kennedy was sitting, and a bullet passing through Kennedy's neck would have struck Connolly exactly where it did strike him.
If you really look at the photo of JFK and Connally siting in the car, you might notice that the angle of the pic has the front end of the car at a downward slope. Righting the slope might just place JFK and Connally on an even plane. What do ya think?