For one of the ambulance agencies I work with, my trainer for my first few shifts is the kind of person who questions "why" for everything. When you discuss the call afterwards, he'll ask "why" you did everything, will ask for more details, will ask for you to remember the physiological reasoning behind what's happening and why what you're doing works. When there was a question you should have known the answer to but didn't, it made you feel stupid and insignificant. To a lot of people, especially those who hadn't worked in high stress situations before, they couldn't stand training with him, because to them he came across as belittling, but those people who could deal with the constant questioning learned a lot and didn't forget the important details. All he was doing was making sure that you remembered everything from class- he wasn't asking you to know more than that but expected you to know what it was you were supposed to learn. I can imagine rotations being the same way- your resident, attending, whoever is asking you questions about a condition/procedure that you've been over in class and you don't remember, they have every reason to say "you don't know that? But you went over that in ____ class." Yeah, it may be belittling, but really, you should have known that.
Note- I have no idea what is constituted as "belittling" in medical school, but that's how I'd interpret it based on my experiences.