There was a question just posted that was closed (rightly so) due to being trivia and not relevant to the understanding of the movie. I know the answer to this question and could drop it into a comment on the closed question. Is that bad form or okay?
While it's something that you can do, I really can't encourage this behavior. The reason being is that, if people know that they'll still get an answer, they'll ask an off-topic question on purpose to still get their answer.
I think the best course of action is to convince these users to enter chat so that you can give them the answer to thier off-topic question there.