If this was my little boy they would have called the police on a screaming mother. There was a teachable moment and they let it pass.
If the child was gay I’m sure they would have said “don’t bring it to school again dear” patted him on the head and sent him on his way.
If it was my little boy, they would have called the police on a guy using a baseball bat as a club--and they would have called an ambulance, or maybe the county coroner for his victims.
I would meet wiyh the principal and make her talk to me until she couldn’t hold it any longer.