Haha,
My worst accident so far is i spilt a whole bottle of aqua+ down myself while in the middle of a water change, thrown the water away... Hadn't added any more in.
I had to lower my filter so the media was submerged and go to the pet shop leaving my tank half empty (or half full).
Because i used to have a tank in the spare room and it was feeding time, i was walking across the landing going to the other room with an open pot of flakes not realising the dog laying on the landing and resulting in me going flying in a shower of fish flakes. I giggle at it thinking of me falling over my dog shouting 'NOOOOOOOOOOOOOOOOOOOOOOOOOOOO' with loads of multi-coloured flakey smelly things coming down on me, oh what a scene.