If the hard drive gets disconnected for whatever reason, all the media goes offline. This makes sense. But when the hard drive re-mounts, why is it such a disaster for Final Cut? Why must all media now be painstakingly re-connected? All files are still in the right place, the file references in Final Cut have not changed.
There must be some technical explanation for why Final Cut cannot simply pick up where it left off. I'd rest a little easier if I understood.
Simple answer is that if you save the project file with media disconnected it remembers the disconnect state and you have to reconnect. This is a pain but if your media is well organised, and you have studiously avoided file name duplication, it can reconnect quickly.
I have had this happen and the easiest thing was to shut down without saving.