Re: My contribution ...
My contribution to the hall of shame involved accidentally recursively deleting /usr/bin, or most of it at least. We were a poor university in the 90s so only backups of user directories. Luckily the system was one of 4 HP 700 series running HP-UX we had scattered around the department so I managed to restore from one of the other boxen and all was good again. Pretty sure everything was restored, no one ever complained at least.
It's amazing how sudo makes one think about what one is about to do, most days.