Comment 25 for bug 579876

The correct title and text for this bug should be:

"When a home-encrypted user's password is forcely changed by an admin, there is no warning message that this will break encrypted folder automount"

The ideal solution would be to ask for the user's current password in order to update the wrapped passphrase, but the warning would be much better than the current situation.

Other than that, not much more can be done.
Protecting your data includes protecting your data against the admin users too!
Especially because it includes someone who stole you computer and root'ed into it with a LiveUSB...
That's the whole point of encryption...