How is that stupid rules somehow? You agree to the same rules every time you log in.
The rules are clearly stated on the agreement page.
You have been using chat for well over a year and know very well what is or isn't permitted, even if you haven't read the rules, because ban messages are public every single time someone is banned.
What you should have done is reported him. Baiting such things is not permitted either and it'll be viewed same as seeking such content.