So the one that I was thinking about today was the time we had a 3 hour circuit outage because... drum roll... the UPS was turned off! You got that right, this poor bloke had spent three hours on the horn with support personnel at HQ trying to figure out why the router wasn't working, when all along the UPS powering the entire rack was turned off.
It seemed a bit obvious to me when I rolled in and nothing in the rack was up, but I guess he just didn't think it odd that nothing was blinking green. I can still hear him trailing off... "none of the lights were red". Seems he figured that since nothing was in error state, it was all good.
Cheers all!