Sniper Shot (Spoilers)
The logic they used to discover where the second shooter was is unrealistic.
If you shoot someone through the head the trajectory of the bullet would go of course. Unlike a video game the bullet would not cleanly pass through a human skull, there's even a chance, given the distance of the shot that it might not exit the victim's head at all.
Also upon striking the head the bullet as tough and as fast as it is traveling would suffer fragmentation and could not possibly cleanly penetrate the stage's pillar like the first sniper's shot.