The perp flipped the cop off. What does he think is going to happen?
He probably didn’t expect a supposedly trained “professional” to act like nothing more than a stinking short fused street gangster. But then again, I didn’t see that he had flipped anyone off.
He was face down on the sidewalk, it’s much more likely he was trying to get something out of his eye than try to goad an armed and dangerous individual who had proven mentally unstable by the threats he was making.
The officer was wrong to touch the guy in any way, shape, form or fashion unless it was to arrest him for a criminal act or to prevent him from coming to harm. It’s “Protect and Serve”, not stomp down and threaten with brutality cause you’re unable to control your temper like any reasonable adult is expected to do by civilized people.