Well, it turns out the teachers' reaction was a misunderstanding for the child beating up a little girl. But to react to a suspected bully with extreme force like that, unrequited is an understatement to say the least. This is called jumping to conclusions and excessive use of brutal force. The child put up no defence, and as the teacher lurched toward him in the corner, he sank to the floor submissively out of fear for what's to happen to him.
For the punishment, court will happen eventually and the real charges will be layed upon the teacher. For now all that can be done has been done, firing her from her job. Hopefully the child will not suffer too much mental trauma from this event and that he can move on from this. I do wonder how much the compensation will be after the trial, beating a minor without reason doesn't really bode well for you.