The bartender didn't bounce him because she was smaller than he was. There werent' a lot of people in the bar, and everybody else had just either been letting him get away with it, or they just didn't feel like fucking with it and left.
As far as why its little man syndrome and not just being an asshole. Well, I suppose he could have been an assshole, but I just thought that there had to be something else to it.
I think that at some point it does matter how big they are or how badass they are. I was in a bar one night and one of my friends who was a prick started making fun of some dude in there. I finally pointed out that the guy he was making fun of had a Ranger tat on his arm, and that he shouldn't fuck with him. Even though the guy wasn't bigger, he was definatly able to whip some ass. I think that me being bigger was something that the guy should have just been able to see.
It also crossed my mind that he probably had a knife on him, just because of the bar that we were in.