Well, an update:
The cause of the flooding was the second floor washing machine hookups. They were in the closed "off" position when the hosue was inspected, I was present at the inspection. Somehow between that event and when the water was turend on, both valves were turned to fully open "on". Without a washer attached.
I had no access to the house interior whatsoever during that time. There is no call for those valves to have been opened after the inspection for any purposes whatsoever. So basically when the water was turned on regardless of my presence inside the house or not, I would have been completely ******* though not perhaps to the extent that the house is now.
At this point I pretty much have to walk away. I'll know more tomorrow.