Well I have watched the video time and time again trying to work out what the fuck pizza and rooster are seeing that I don't and I have come to a few conclusions.
It starts off badly for the idiot, as I think he trips, goes into that roll and comes up embarrassed.
I know that my thoughts from this point won't stand up to pizzas rigorous standards of proof, but I get the impression that wearing the badge and carrying that gun haven't quite given him the boost in confidence/respect & hero status he craves, so now being at a disadvantage he gets angry and defensive and tries to regain his standing by shoving people around, this works for a while and gets some of them to sit down. But as in every situation involving a teenage crowd there is a mouthy girl, most of us chilled people know to avoid these like the plague but she is probably the kind that gave him a hard time in school, so he can't and this is where his life goes down the pan, cos' he quite clearly loses it and acts like a cunt, and when two rather brave chaps try to intervene the twat pulls his gun. The other cops probably muttering “wanker” under their breath have to step in before he shoots some one and so he ends up sitting on the fit chick, which is most likely the closest he has come in years to some action. Sorted, that's what happened, take away his badge.