I disagree with the teacher, she should have her facts straight before she teaches the class. The student should have a more respectful way of telling her she is wrong, but he was still correct. If I was his parents and the teacher gave him detention for that I would have a big problem with that. The teacher should admit she is wrong and apologize to the student and his parents. If she does not apologize the parents will surely think their son is lying to them and make a bigger deal about it than it really is.