@ Topic,
The first thing should have been to report the incident to the school
authorities for the to take appropriate action, so the this ugly situation would not be repeated, . . . . . , .
And then have a very long talk with your child on the importance of standind
up for him self, no in a violent mannet but firmly,and then whenever things
escalate he needs to bring it to the attention of the class teacher.
Totally in support of ypur opinion, i will also tell him to be able to stand for himself in case of another time