My guess is that Tracy's mom may have wanted to avoid publicity and having her daughter's name on the news. Even if the courts and the media hide her name (because she's a minor), her identity would eventually be leaked given that all the school would become aware of the illicit affair. So, probably Tracy's mom would have been satisfied with the teacher being fired.

Wasn’t he teaching a class about ethics?
That and the subject of morality came up in a class he was teaching.
Which I think is the ironic plot of the movie since no one had either throughout it.
Especially Mr. M.
Everyone was doing something wrong to hurt others to get their way and not giving a **** about it.
How you die does not redeem how you lived. - A black pastor on the life and death of Charlie Kirk

The good ol' days
My password is password.

Exactly. McAllister didn’t want to throw his friend under the bus either. At least he was able to talk sense into him.
My password is password

It was a different time back then. Lolita was not as taboo during the days of Phantom Menace.
My password is password

Tracy would have found a way to come out on top since her mother was an attorney, and the law would be on Tracy’s side since she’s underage. McAllister did scold the guy for what he was doing at least.
My password is password