WOW. Some of you fuking idiots are the same ones who said the cop in the other video was in the wrong for punching the guy in the back seat of the cop car in the head for kicking the glass. WTF. I think there are a lot of women beaters here. Chick simply tries to sneak off and winds up almost out cold? Please, she didn't deserve to basically be sucker punched, elbowed. That cop rushed her and meant to take her down hard. U guys are fuked.
The cop appears to be in reasonably good shape. That's kind of important because it would lead you to believe he didn't need to use all his strength to take her down, didn't fear that he could not over power her etc. Secondly, her beef was with the mom, not the cop. Cop isn't pissed at her because she spit in his face, slapped him, fought him, called his mom a bitch...so there is no underlying obvious motive for him to knock the crap out of her. I'm pretty confident given 10 minutes, the video and a jury of 12 reasonable people I could easily convince them the force used in this case was unintentional assuming they needed any convincing after seeing the video. I think you are making a mountain out of a mole hill