Similarish happened to me...
ILike a total idiot, I'd messed up the order of a new filesystem in /etc/fstab - I placed it before it's parent mount. The server was used for interdepartmental stats reports by various boses, along with being a site dns server, and site internet proxy/intranet.
Months later, one bozo from the windows team went to do something on one of their servers, and did alt-ctrl-delete on the wrong keyboard, trying to wake his box from the screensaver (who does that anyway?? Pressing "SHIFT" surfices._
Needless to say, the box tried to reboot, and failed due the fstab entry, about 10am. I wasn't in that day, and so the machine was down until a colleague started work at 3pm..
There was a bunch of Unix support guys on site, but no-one had a clue what was wrong.. sigh.
Still, it was my stupid cockup...