the magic bullet was explained in the show i watched. i have it recorded on my DVR at home but i can't remember the show's name or he channel.
but what i DO remember is that they took the Zapruder video and used a technique called rotoscoping (hand animated tracing) to make a 3d animation of Kennedy's assassination. while setting up the animation, they found out why it seems that the bullet made a sharp turn in between Kennedy and Conally like in this picture.
the 2 main things that the public doesn't realize about the circumstances surrounding the magic bullet is that 1) Conally's seat was not directly in front of Kennedy's (it was a little to the left) and 2) both men's bodies weren't facing directly straight forward. Kennedy's body was turned slightly towards the right in order to put his arm on the door and to face the crowd. here's a more accurate depiction of the magic bullet...