I just wonder if someone HAD stepped in if that guy would have laid off. I mean their silence in a sense showed him that he had all the POWER in that establishment. No one was going to stop him or tell him he was wrong. They said so by doing nothing. They in a sense gave him approval by allowing him to continue. They were all afraid. He could do anything at all that he pleased.
I HAVE stepped into a somewhat similar situation. Between a guy not quite has heavy but just as tall who was attacking another man who was somewhat smaller but not a wimp in the least. I simply grabbed the man's collar, looked him in the guy from almost a foot below his eye level (
), and said low and quietly "Don't you dare. Back off." The situation diffused. That made the number two against one. Albeit one (5'5" 130 lb) woman and one somewhat smaller man against the attacker. The point was he lost the "power" in the situation. No one was GIVING him power by being afraid and no one was going to allow him to continue without at least some injury.
I really doubt that the attacked man (I don't like the term victim) would have suffered quite as seriously if someone had grabbed a rolling pin, ran up between them and said "STOP and LEAVE now or else." Don't make any promises like "You'll loose your hand." Simply say "or else" - simple psychology will cause their imagination to come up with worse punishments that even you may believe yourself capable of. That can sometimes be sufficient deterent. I'd take one hit physically to ensure that I knew that I'd done what I could to stall the confrontation.