Could also be a situation where they couldn't believe that it was actually happening. Kind of a "shock" response, or lack thereof.
Sometimes, you just have to harness the inner bouncer and start tossing commies. Well, if you're young and strong anyway. I remember breaking up a fight in the neighborhood watering hole one night - grabbed the guy by the collar and belt and tossed him out the door like a garbage can. If I tried that now, I'd probably be on the ground first. Old age has its ways...
Could be. Not so young myself any more - but I still have a hell of a punch...