There is no universe in which you watched the relevant videos here and come to the conclusions you just did. None.
1. The video of the car driving off shows he isn't speeding or otherwise suspect. If the cops had wanted him to stay at the house for reasons that would have instigated the aggression they eventually showed toward him, they wouldn't have let him leave.
2. There is no indication in the videos that he is speeding at any point; he pulls over without incident.
3. He _CLEARLY_ has his hands up at every point in the video until the cop smashes the window in onto him and reaches in and punches him. If the guy was actually trying to take his gun, there is no universe in which the cop STAYS in that position and yells at him "don't take my gun". If he actually thought he was taking the gun, he would not have stayed in the car.
4. In what universe is it ok for a cop to repeatedly punch an already subdued person in the back of the head multiple times?
I'm all for the cops and I'd hope that even in a situation as cut and dry as this, that what they did was born out of a misunderstanding of a situation or something close, but there is no possible way you can consider what they did acceptable.
This is so patently stupid and funny that if it wasn't overtly racist, I'd put it in my signature.