So a man waiting to pick up his kids from school sits for a few minutes in a seating area where he reasonably thinks he has a right to be, private security asks him to leave, he thinks they're harassing him because he's black, and they call police. This is where the video begins, and that conflict is already over. The man is walking away from it and toward the nearby school where he is to pick up his kids.
So problem solved? It could have been.
Instead, this happened: