Cute trick to try with OS X Mountain Lion

Here's a cute trick to try with OS X Mountain Lion (at least this worked on 10.8.0):

1. Make sure that your Mac, when it wakes up after the screen (or the computer) sleeps, asks for user password.
2. Go to System Preferences -> Users and Groups: change the name of the current user.
3. Close System Preferences and wait until your Mac sleeps.
4. Wake it up... and Voila! You won't be able to get to the desktop since your Mac will ask for the password for the old username, but when it checks whether the password is correct, the old username is no longer there!

When I found out about this problem, the only solution that seemed to work is a hard reset (i.e., turn off the Mac and restart). What I think OS X should have done is to force the user to logout and login again from the system. Or even force the user to reboot the system. But definitely it should not have allowed the user to get into this trouble. Macs should have "just worked", right?