Can't add anything else that hasn't been said, but whatever. Here it goes.
That was no way to arrest someone. You know, I'm getting kinda tired of this police brutality and all of us getting used to it. "Oh, that's how they're trained!", "Oh, they don't know what to expect so they have to act fast!" "Oh, you don't know what could have happened if they hadn't knocked him out! Maybe millions of lives were saved!". That's bullshit on a stick.
I'm not saying cops should arrest someone with marshmallows and cotton balls while singing a lullaby. But they should know better than to toss people around like this. Chances are 1 out of 10 people they arrest are actually armed criminals. But does that mean they're entitled to do whatever the fuck they please "for the greater good"? If I go around punching people in the face in the hopes of finding someone who will pull out a gun just to prove that criminals are among us, is it justified?
In this case, like someone filming the thing said, the guy was shoplifting and THIS is how they treat him? Damn, people! Whether that's true or not, that's unacceptable.
Okay, put yourself in the guy's position. Since this is more of a he said-she said situation, let's assume both scenarios:
Scenario A: You're not shoplifting. You're trying to do (Insert favorite activity here), but you've realized your hands are busy with that one game you're gonna buy and you can't let go of it because, well, it's black Friday. You stupidly decide to put it in your trousers. The cops see you and accuse you of shoplifting. Now, at this point, you may or may not decide to do a dance, but at any rate, before you can explain yourself, BOOM! You taste blood and everything goes black. Then you're arrested.
Scenario B: You ARE shoplifting. I mean, one game? It's not like they're gonna miss it or notice it, right? But wait, cops DID notice! Aw, man. Maybe if you leave the game back where it was and forget it all happened, maybe if you just walk away, maybe you can try and talk your way out of thi-- BOOM! You taste blood and everything goes black. Then you're arrested.
Either way, the facts are cops have guns, they should AT LEAST have the brains to analyze the situation (I mean, they were trained for that, right?) and then take the best course of action. In this case, talk to the man and make him pull out the game out of his trousers before doing anything drastic. If he's flailing his arms like an idiot, handcuff him. I mean, it's not like he's waving a gun or as if he could beat all the cops around, 50 or 20 years old.
Of course, we don't know all the facts yet, but it seems the cops overreacted so far. And the worst part? They're probably gonna get away with it because they're cops.