Yes, it's possible, rather unlikely, since there are procedures in place in the OS to prevent this from happening, but disk errors and weirdness can cause things to happen.
This is generally what chkdsk, fsck, and a slew of other utilities are designed to do. They read the allocation tables and match them up with the known file entries... anything amiss causes some action to be taken.
In Windows, you can usually signal to Windows that you'd like a check done by looking in the Properties option when you right click on the drive icons. It might do the check then, although windows seems to be favoring startup disk checks, and it'll tell you that it'll do it on next reboot.
In Linux, ... you can seriously hurt yourself playing with the fsck utility on an active system, which is why Linux boxes generally always do their File-System ChecKs (fsck!) during startup. Simply rebooting will often cause a check to happen. (although I do know that yanking the power out from my home server when the UPS fails triggers one too!) (file system is marked dirty)
OS X? Not a clue. Kinda just figured you Sipped a Latté near the machine and it fixed whatever's wrong with itself by linking with the nearest GeniusBar. (You probably need to be in or near a Starbucks™ too I think)