Wow, Mike, were we watching the same thing? The guy is well over 230-lbs. He was actively resisting. So, it's the police fault that they didn't knock him unconscious so he could be managed? And the guy with the camera: also the fault the police couldn't control him? Or his inflammatory rhetoric? 
Yes, police inflict pain to force compliance. Perhaps you'd like them to ask pretty-please? If you refuse to comply with a lawful police order, they will escalate until you do. Imagine a situation otherwise where people picked and chose what to obey?
Why people like you blame the police is beyond me. This is a clear case of brave officers trying to do a very tough job in unbelievably dangerous and threatening conditions. 
Eugene Police: I commend your patience, calmness, and restraint in handling an out-of-control abusive and dangerous mob.