Backups...
My worst backup incident occurred when I was on holiday, and was thanks to the boss! I may have recounted this before on here.
Back in the days before cloud backups, when off-siting meant taking a set of tapes home with you, I was managing a 486 SCO Unix HP box with a DAT drive, running a number of terminals. Everything was fine when I went away for a week but, just in case, I took the "mobile" phone with me, this was a Motorola car phone attached to a large lead acid battery pack (see https://www.tvfilmprops.co.uk/det/4016/Motorola-4800x-Partner-Retro-Mobile-Phone/ for a picture). I'd left clear instructions on swapping the DAT tape each day but in the middle of the week I got a call, "The backup tape isn't ejecting, what should we do?" My clear instructions were to leave things as they were, don't do anything and I'd sort it when I got back a few days later.
The general manager wasn't happy with this so, without telling me, he called in an engineer from the parent company's support people who was only familiar with DOS PCs and clearly had never encountered Unix before. Apparently without even looking at anything he just powered down the box and proceeded to fix the tape drive, which he did successfully, before powering back on again. At that point he got a load of error messages and not much else. With no idea what to do he just left, basically saying it wasn't his problem as he only did hardware!
I returned the following week to find a server with a trashed file system and the most recent working backup was a week old. It took a few days to rebuild everything, restore the last available data and re-enter nearly a week's work. Did I get any thanks or an apology? Of course I didn't! A while later they relocated the operation to the parent company's offices and I turned down all offers to go there.