Your instincts were right.
The video also has two other incidents, one of another assault and the other of a boy exposing his buttocks, according to the report. Those incidents are also being investigated.
Why is a student bringing a video camera to school?
The headline said crowded school, is it so crowded and disruptive that the teacher could not hear the student yelling for the kid to stop hitting him, no one notices a kid video taping a naked butt?