Ok, here are the facts.
Teen girl in a holding cell kicks her shoe off at a cop. It strikes him in the shin.
Cop kicks her in the stomach (possibly hip), grabs her head, slams it into the wall, throws her face first to the floor, kneels on her back, punches her twice in the back of the head.
Tell me what part of that is fantasy. Go ahead, I'll wait.
Now, it's very possible that he folowed SOP in doing the above, but if so that really just makes matters worse.