This doesn't make any sense. Obviously this person was a trained killer. I think the whole rifle in the woods thing is a prop. It's kind of like the passport they found untouched after nine eleven. I believe it's a distraction to make us think along the line they wanted, or to make us look in the wrong place. A kind of smoke and mirrors or a slight of hand.
It's almost like somebody's making war against us, by deception.
I asked myself the same questions. The angle of his position doesn't line up with what we actually saw on camera either. The angle of bullet entrance and exit suggested to me that the shot came more from Charlie's right than from the rooftop position in the mainstream narrative.