If there was a crash it would say Server offline, not have server online with so and so people. And yes, it does go down this quickly, it does like every day, when lots of people log off. And if it was a crash it wouldn't slowly boot people off, it would be all in one go.
Updates also don't really affect the server unless there is a patch that requires you download the new patch to play, but if it was doing that, you would know, rather than think it was a crash.