A plumber came to our house yesterday because our main floor and upstairs (we have three floors and the basement toilet and tub were operating properly) toilets and tubs were backed up. He decided to remove the upstairs toilet after he pumped out the water from the tub that was left standing. He then augered the toilet and said "ok, I think I got it, let's turn on the water in the tub here just to be sure". After the water in the tub had been running for about a minute or two, he said "let me go check the main floor toilet to make sure that water is not running over" . He went downstairs and found that our entire dining room and hallway were flooded with brown water. The hard wood floor are ruined and so is our oriental rug and the grout in that bathroom is stained.
My question is if it is his fault for running the water in the tub that we had the flood? Shouldn't he have thought to have someone stand at the main floor toilet to make sure it was not overflowing when he turned the water on... in case he didn't actually remove the clog? It was a very large amount of water and I can't imagine it could have just come from that toilet...
(also, we never found out what was clogging the pipe, so he didn't know for sure that he had gotten it out).
Thanks for your help!