The officers were dispatched to remove tents, not protesters, tents from the quad. When they arrived they were surrounded by 200 protesters, giving them no way out, and cutting them off from back up. So whether or not you view the beautifully edited snippet of video and think it is ok to surround police, and cut them off from back up is ok, or not, you get what you get if you are warned, and ignore the warning.
To me this looks like a cop who was trying to incite the crowd into violence. He knew the crowd was agitated and he wanted to push them over the edge and get them to react in a violent manner by attacking the protesters who were sitting and posed no threat. I would say his behavior was aimed not at protecting the public and property, but at inciting the crowd to become violent.