The best/closest I have is that where I once worked, we had a NetApp that allowed it to be upgraded to a version that it didn't support (it wouldn't boot) which was not how it was supposed to be... Anyway, we should've been able to fallback but the jump we tried to make screwed with paths to the bootstrapping/startup and while normally the previous version should be recoverable...well it was not because of where the upgrade process failed.

So we were trying to recover it and I had a "It's a Unix System, I know This!"-moment and was able to manually type in the path to the previous binary during an emergency/rescue prompt (based on deductions from forums, the current failed loading message, and some obvious things like architecture) and got it up and going again.

Documented that, internally, to the best of my ability.