@Tcof
1) She didn't know AND REFUSED TO LISTEN. She had every single opportunity to actually listen AND REFUSED TO LISTEN. Let's say there's a person who is told that milk sold in stores comes from cows. Then they refuse to believe it despite being told time and time again. She doesn't want to learn. She doesn't care.
You say his explanation didn't sound convincing and that any sane person would think the same? Says who? You're the one saying that it's the only conclusion. The teacher is the only one who thinks that it's so obvious. The only reason that the teacher thinks that it's so obvious is because she doesn't care to see the fact that she's wrong.
2) So then it's good to ignore the honest pleas of one student because other students are bad? I'm sorry, that's what makes you a good teacher? Hey, teacher, there are some bad students in class, therefore you should treaty every single one of them as bad.
That is what we call a bad teacher. That is what we call horrible.
The problem is that you ONLY see her perspective. The problem is that SHE only sees her own perspective. She refuses to listen. What is so hard about this? In literally any other situation, we would call out this kind of person as being prejudiced. She is literally pre judging. It's literally prejudice because she won't listen.
Let me be clear. If he never told her that he was a boy, then this would be fine. If he told her only once or so, then maybe that would be fine too. It would make sense. He went above and beyond. He tried telling her over and over and over. She didn't care. She didn't give a single crap about what he said. To her, she was already right no matter what. That is called prejudice. That is called horrible.