The kids on the bus are lucky he didn't kill them. Grabbing her breasts is sexual assault and should be charged as such. Throwing condoms at her and spitting in her hair. Hitting her....all assault.
My daughter is the same age but able bodied and healthy. In his position I would have been tracking people down. I personally think he showed remarkable restraint.

The fact that the teachers et al did absolutely nothing about it is disgusting. If they themselves had gone through one bus journey like that there would be lawsuits for one and they'd probably be permanently traumatised. This should not be less of a big deal when it happens to a vulnerable child.

The kids responsible should be facing criminal charges. What exactly did anyone expect her father to do?