Taking the tough guy lawyer approach isn’t the only option. I think being a lawyer, and using that to intimidate others, without any real intent to take legal action, is abusing your power as a lawyer. Just go deal with the situation like most non-lawyer adults. Go communicate like a normal human being.

[edit] I’ve read through your other posts and it sounds like that’s the approach you’re going to take, which is to involve school staff and let them handle it. If that doesn’t work, then go to your Plan B.