That teacher is a disgrace to the profession. When you have a student who cares that much about a topic, and claims that you're wrong about it, The teacher should ask a student to write a report on that subject, or at the very least explain further what they meant by that. Then thank them for their contribution, and give them extra points for class participation. If a student is questioning what you are saying, then they are thinking about what you are saying. That's what school is for.