Usually I would never see this, but my line of work requires that I suspend disbelief.

Scooter user has a FreeBSD server and is "doing maintenance". Later I discover they're upgrading from 6.2 to 7.0. Usually this isn't an issue, but they went and changed root's shell to /usr/local/bin/bash. Now, anyone who knows anything about upgrading FreeBSD knows what happens between major versions. Libraries change versions, applications break. Not a pretty sight.

I, being the only FreeBSD admin on the floor at the time with some seasoning, am blessed with the task of cleaning up behind this genius after a couple of other people can't get root. Meanwhile, Scooter has the nerve to start screaming "NOW NOW NOW ASAP OMG BROKED!!!!1!1!!OEN"

Since I have never had to deal with this before, the su(1) had the answer I required. It was, however, not readily apparent that it was the answer. After some twiddling, I was able to get in by using 'su -m' and saved the day. Now all I need to do is take the time to write up some "best practices" stuff to teach folks.