When I was in high school, we had a similar situation go down one afternoon while waiting for the bus outside.
Girl got put off the bus and refused to go with the SRO officer.
She ended up railing him in the face half a dozen times before he swept the leg, forcibly held her down, and handcuffed her.
He was being assaulted and used less force with her than this guy did with what looks to be a middle school or high school freshman girl.
I fail to see what would warrant that sort of response.
It's one thing to subdue someone. It's another to do what he did.
He looked bloodthirsty and there's no way this should be accepted or excused.
Hard headed or not, that's a child that was posing no threat.