I can't add anything to address the situation that you've described and while I don't agree with the teacher's method, I I would think it wise to use the situation to talk with your child about how throughout HS and then on into college to an even greater degree, your child will need to adjust to teacher expectations, habits, quirks, accents, teaching methodology, etc.
Sadly, for as odd as we think HS teacher's methods and expectations may be, in college through two sons, I've seen scenarios much magnified as most college professors, while proficient in material, have zero training in teaching and it often sticks out like a sore thumb.
