What I'm seeing here is people who cannot help themselves being abused. The police in these cases are harassing, maiming and killing those who cannot defend themselves.
Not sure if anyone has seen it but this reminds me of the documentary Titicut Follies and the treatment of prisoners/patients. The guy in the car accident probably was so far in shock that he didn't even realize the police were talking to him, couldn't comprehend any orders and the police probably thought he was some kind of mental patient. Him climbing onto the cop car was just trying to escape the pain the police were putting him through, it's like an animal running up a tree to escape from another.
It all pisses me off, just because a person is committing a petty crime (homeless man case) does not mean they should be beat like an punching bag. Abuse isn't reform, look at Norway's prison system and statistics compared to the US. Heck, it's just like the parks, respect gets respect. When the police respect us, I'll respect them. Attitudes, ego's, supervisors looking the other way and abuse doesn't make me want to respect them.