Hey I read your thread but it was closed. Just wanted to say everything depends on the context. We don't know your instructor and we don't know you in terms of personality and mannerisms so I disagree with the majority of the posters who put you in the wrong. At the same time I think there's not enough information for anyone to say you were in the right either. The ones who can accurately judge the situation are the people involved in the situation. So even though my opinion is inconclusive, I do have one thing to say: that tact must be observed when speaking to someone who teaches you, regardless of their rank, and that opinions of a student should be respected by the instructor if it was respectfully worded. So tactfulness and respect should go both ways, which we clearly cannot determine without reading emails from both sides lol.