Damn, that must have been a big dude and heavy loaded shotgun. Another basic law of physics is that "for every action there is an equal and opposite reaction" so either a much bigger guy shot him or the guy shooting hit the ground too. It could also be that since people are the weakest of all animals with the lowest pain tolerance these guys were reacting to the mental shock and pain of being hit as much as anything.

I won't be wronged. I won't be insulted. I won't be laid a-hand on. I don't do these things to other people, and I require the same from them. John Wayne-The Shootist