It's a bit hit-and-miss.  The problem is that many cops feel that they must be in total control of any situation, and want to subdue anyone who could challenge that. Also, there is an insane idea that cop's can deal with things by rapidly escalating, rather than de-escalating the situation. If the cop in this case had tackled and arrested the man instead of just hitting him, the man would probably have less legal recourse than he does now. The cop could say he felt he was threatened and had to subdue him, and it is hard to argue that the cop is lying or was out of his mind when thinking that. It's a ridiculous system and cops are given huge amounts of leeway, to the detriment of the citizens who may have their career destroyed by an arrest record. Many cops are self-restrained and don't abuse it, but the ones who do abuse it are rarely (if ever) punished or fired. The police union is very powerful and defends them under all circumstances.