Should I post an answer to an off-topic question after flagging it?
I seem to find off-topic questions that I can give a good, useful and correct answer to. (The specific question tonight is this one, but it's happened several times this month now). Other users have clearly deemed the question worth a response; I think I can provide a better response based on the original question and the provided comments, but I also don't think the question fits well on StackOverflow.
By answering, I feel like I would validate the question's existence on SO. On the other hand, other users clearly deem the question appropriate enough to warrant answers.
What's the consensus for this situation?