ktharavaad (http://news.ycombinator.com/user?id=ktharavaad), the user who said he could clone SO in a weekend (http://news.ycombinator.com/item?id=678501), hasn't commented on HN since before the weekend (http://news.ycombinator.com/threads?id=ktharavaad), so I'm guessing he learnt his lesson.
That said, I think people are making too big a deal out of this. Even the best of us occasionally end up shooting comments from the hip without thinking about them first.