If the story as outlined by @jonri is factual, the only issue I have with the teacher would be her stating why she was withdrawing her LOR. When asked, I would have stated there was an action taken that was egregious enough from my perspective for me to withdraw my LOR and directed the college to the school. I suspect if she had done it this way, she may not be in the situation she is in. Or maybe that’s just my optimistic nature as I would hope parents would find it equally egregious their son uttering such horrific words and understand a teacher having second thoughts about a LOR.