In my experience it was always a kid being a shithead. Kids are unrepentant assholes especially if you put 20 of them in the room and try to make them learn something. In my extremely consistent experience they're the same shitheads that complains school didn't teach them anything useful despite the fact I was sitting next to them in the class where that was being taught but they were just playing the penis game instead.

I have never seen or heard of a teacher punishing a class for the shortcomings of an ND student, that reads an awful lot like climate protestors are bad because every vehicle is being driven by an incorrectly chatged innocent individual on his way to a parole hearing.

We had ND kids in my school, I got along with most of them they were all stoked when we got to the seperated classes and we could actually focus on learning physics because the teacher didn't have to argue with students that they couldn't dip in class and they had heard them call her a removed everytime she walked by their desk.