It just happened (again) that someone removed a homework question after getting responses in comments. I realized this because the OP had responded to my comment before deleting the question, so that I got a notification in my inbox that led nowhere.
I am asking for guidance here how to avoid this kind of thing (or, as the case may be, why I shouldn't mind).
I feel that there is something dishonest about this. Both on the level of possibly hiding the question from the teacher and on the level of not thanking for a response (either with reputation or with a thank you).