How much more back story do you need when you see two guys backing away not fighting and an ***hat slapping faces and acting like a total drunken chimp? If there was a real confrontation and he reacts that way instead of throwing down, he deserves what he got. It's pretty clear the guy was a drunk taunting guys because he thought he could without counterattack, then enter stage left: boom. There is no back story imaginable that would change the interpretation of those minutes on video.