No, you don't sound arrogant at all. Yet, I do find it troubling how some teachers assess intelligence and can force their assessment on individuals when they are not really qualified to do so. And sometimes, what it can boil down to is how that teacher isn't a very good teacher too, could be they may simply be too black and white and fail to recognize the very important grays. And this particular teacher ONLY focused on the behavior and never THE IMPORTANT WHY. What I witnessed my older brother experience would be considered child abuse today.

Yet, it's not just teachers but often all different kinds of adult authority figures that can contribute to condeming when it's simply not deserved.