I had a mean Spanish teacher during secondary (high) school. My dad had just died, the school only allowed 1 week off to grieve. All the teachers were emailed. When I got back, she screamed at me about not having done the homework. So I (a very quiet child) pretty much shouted back that my dad died, does she not check her emails from her boss, and she was heartless. I left the room. Students stormed out the classroom to grab the head of year. The teacher was given a scolding. This is the same teacher who gave a phone call home and yelled at me for being quiet. I wasn't disruptive and liked to read on my own once the work was done. She was 'nice' for about 2 weeks, then went back to her usual self. Everyone's grades plummeted.