I don't think anyone is suggesting anything but truth and honesty and disclosure, but when someone doesn't even give the site admin a chance to correct a potential problem (good thing this wasn't actually a serious exploit), they are just being irresponsible towards the users of the site in question and the community as a whole.  I for one hope that when/if someone does discover some potentially damaging exploit that they won't put us all at risk by instantly sharing it with everyone, including those who will jump at an opportunity to take advantage, at least until site admin has had an opportunity to take action.