Well, they're not going to crack a ton of passwords that quickly, and I'm guessing that they're testing against the live server, so if the password doesn't work then surely the most obvious answer is that the password has changed.

A lot of people have already stated that one way around this would be to change your password before the feds have had a chance to crack the provided hashes. This would surely be a similar system.

Of course, I don't know if this would work at all. I was basically thinking aloud to see if this idea would have some merit.