I've seen more shootings in review tapes and in real life than you'll see in a video game. You don't shoot around people like in the movies. Especially without a precision rifle and special match grade loads. As for all the stage magic -- with that many cameras no way in hell. It's much more unlikely than a crazy graze. Like others have said bullets do crazy things when they impact, and if it was target loads and bullets which is likely if he just bought the ammo that day without testing they can do even more crazy stuff.
You're having to make so many more assumptions with your theory. Also check out videos of the near miss shots that have been projected into a 3d visualization.