I agree that the white guy was very stupid to play tough guy games with this guy. It was dumb to stride forward with a menacing stare and his hands behind his back. However, on a serious note, we make light of these kind of things as we are totally desensitized to them with the advent of Youtube and cameraphones, but all it takes is for that guy to crack his head open as he falls unconscious to the floor and you've just witnessed a possible homicide.
The hitting him while he was down was scandalous and the running away and giggling like schoolboys showed how pathetic and worthless that 'gang' is.