As the OP said, we have no idea what happened before the beginning of the video. Plenty of folks have led the police on chases, then run into a crowd screaming "police brutality" and "I did nothing!" while the police cuff them. All the crowd sees is what's in front of them, which is a "victim" being "abused" by the police.
The same goes here. Let's refrain from general commentary on the situation until we have more information.
In the depth of winter I finally learned that there was in me an invincible summer.