I just think that these mistakes are part of the game, and there is no need for these safety nets.
I actually have literally just made the mistake of finishing a project early. Yes its irritating, but I only have myself to blame, and its only set my team back 5-7 days.
it would seem unrealistic not to have some kind of undo... I mean I cannot imagine a situation where you cannot change your mind (say by the next hourly update) in life.