I think sometimes people forget how instantaneous so much of our communication can be. Certainly there are plenty of emails or blog or forum posts that sit there for ages before there is any sort of response. So, sometimes people put it out there that something is done figuring that by the time people read it, it probably will be. Forgetting about time zones and insomniacs or those of us who spend inordinate amounts of time on the net.
So you do that, and that's the time that people start emailing or posting back that they can't see it and are you sure you did it. And in the ways of the internet sometimes people then gather around and start wondering what happened and why you would say that it was done when it wasn't.
And I think in most cases the person who said it was done didn't mean to lie or mislead, but they set an unrealistic expectation and now people are mad. Often if you say, I'm really sorry for the delay, I am working on that now and hope to have everything done in the next week, people will be fine. Okay, some people will whine, but it will be less people than in you say it's already taken care of and then everyone goes and looks and sees that somehow it isn't.