TG, I hate to disagree with you but I do take a different approach. I ensure that HR or another rep contacts the candidate in some way shape or form even if the application is still being considered, delays that suddenly pop up, or that you are no longer interested. I have a list of candidates that I interview on my files at all times and follow up with HR to ensure that they are notified of their status. Now if it is still within the decision making period that I notified the candidate, then NO I don't send anything, but once that decision period has passed ,then they get notified. Have I ever slipped, yes of course, but as a rule they get notification.

IMHO, It is HR's job, but it is up to the hiring manager to see that they follow up with the candidate and the hiring manager can contact HR or the other designated rep by email. As for your scenarios, I don't blame you for reconsidering. I know I sure would if that happened to me, knock on wood, it hasn't. I would imagine that they needed you in this case more than you needed them so you could reconsider. I would reconsider as well, although it does come down to bargaining power and how bad do they need you and how bad do you need them and whether or not they are gamefully employed or not.