But, to me, it felt that mistakes actually *were* more costly for those who were in the minority.
I'm pretty sure that that's not just feeling; it is frequently the case, and very relevant in a work setting and in small university classes, and something we need to fight against.
Large (100+) classes are common in early years of university and far too impersonal for assumptions/prejudice/expectations of professors etc to be directly relevant. Many fail and the reaching out consists of letting them know when the resit is. Now, even this may be interpreted differently depending on the student's background (oh, this is normal versus oh, the people and the system don't care and view me as unworthy).
Your point may be more relevant when it comes to tutorials/support classes.
Did you have Garrity as a lecturer, Zan? I just watched https://www.youtube.com/watch?v=zHU1xH6Ogs4
, very good. I also have his "All the maths you missed" book.
The idea that one should be very cognisant of one's students' levels of mathematical maturity (and that they can be raised) seems important.