Kudos; that's an admirable attitude. In cases like this specific one, in which the original comment contained exactly one false proposition, and the immediate contradicting reply is easy to understand on its own, I have decided (and have seen others also decide) to just delete it so that no one is confused. (Like possibly 'Havoc in the sibling comment.) If there were something wrong with deletion then HN wouldn't have it. YMMV!