Well, I play PUBG, and in this game one of the buttons has your character hold their breath while scoped in to an enemy to improve the accuracy of the shot. So I wouldn’t totally throw out how a video game might of helped the shooter. If he were a novice, he would at least know that you need to control your breathing when you take a shot. I don’t believer Tyler was anywhere near a novice, probably is an expert shot.
Yes, holding your breath is necessary for a long shot as long as you don't hold it too long. That comes with your first shooting lesson.
I have no idea what that might be. ;-D