What is his “nonsense”? It’s reasonable to not allow people to cross their biological gender league. He’s seen how biological males have absolutely destroyed in biological female leagues.
I bullied a kid in middle school to the point where he switched classes. Teachers didn’t panick and kick me out, rather they listened to both sides and let us figure it out. We talked and became really good friends, even to this day!
Humans aren’t perfect. I’m not saying bullying is good, but the best solution is not to punishment. I’d certainly spiral out of control and become a monster had I been kicked out.