AIBU to ask if smart-arse is a ‘rude’ word in primary?

[confusionberry]

Help me out here I’m confused.
Supposedly, kids are not allowed to use the term ‘smart-arse’ in the school.
But, the teacher called the entire class smart-arses in anger, told them they are loosing their ‘privilege time’ and instead they had to write letters about ‘what they are bad at’.
Is any of this unacceptable?

Why are they losing privilege time?

The other two things are awful.

so I’m not going crazy thank you

My DS is 8 and has asd, he has just completed some therapy work to increase his confidence, separation anxiety etc and has done brilliantly! Having to write down all the things he is bad at would set him 100 steps back and I can imagine there are many other children in a similar situation to him or have other reasons why this could affect their mental health. I would be at very least finding out the other side of the story from the staff if you heard this from a child (DS is very blunt and unable to lie but my overdramatic 5 year old DD has come out with some very questionable stories 😂)