I really don't understand why it matters how long it took. The community votes to close similar questions that quickly all the time. The vast majority of which either get solved in the comments and become too localized or the OP pulls the disappearing act and never actually replies to those comments to improve the question.
If Robert had closed the question after 15 minutes instead of 2, nothing would have been different. It took the OP near 20 minutes to reply to the comment. Sometimes it can take the OP hours or even days to get back and actually check the question again. I don't support bad questions sitting around open for any period of time, even if it's just a few seconds. Single vote or not, if it deserves to be closed it should be closed.
As for giving him a chance, the OP already had a chance. They can take as long as they want when writing the question, and this person chose to wing it and throw something out there that wasn't complete. Now it appears he's edited an answer directly into the question.
I agree that newbies can sometimes become confused when their question gets closed, but the comments are listed before the close box, so if they didn't bother reading them to find out what they need to do to fix their question (because in most cases there are comments), then they obviously don't care.