“lacking intelligence or common sense” Source
Would you as a Year 12 student walk adjacent to a four lane road and throw a ball behind your head to another student to catch? And, when the inevitable happens and it bounces across the road would you ask the teacher to retrieve the ball? And if confronted by said teacher would you grab the ball and run away and hide like a five year old?
In the heat of the moment it would be quite simple to call a student “stupid”, rather than the action. And, if this is the third such “event”, and you actually think the student is stupid would you call the student stupid?
Would that be appropriate “feedback”? I think some teachers have the patience of a Saint.