One of the things that helps conductors live longer than trumpet players is that they are on the right side of the baton. We don't get paid for "liking" what the conductor does, we get paid for getting in THEIR HEAD and giving them what they want.
We can't determine if the thread owner has ears, musical common sense or anything else, so instead of dumping on the teacher, perhaps the best route is to promote communication. No conductor likes to be called out in front of the band, so make an appointment, maybe even record the next rehearsal to judge if what you hear is what they hear. Conflict resolution is always best achieved one on one before or AFTER a rehearsal.
I'll bet the conductor is right in this case.