Translation:
I did not get permits to do the work, and the plumbing, electric, and gas were not inspected.
Some/much of the work is probably not up to code, and there's a good chance some of the unchanged parts were not up to code either.
It happens. When we bought our house, one of the "bedrooms" was actually the former garage, converted to a room without permits. When we bought it, that room was not listed as a bedroom. Fast-forward 6 years and we had to do some roof redesign, and we had the contractor get permits and had him do that room with permits and inspections.
Some previous owner cut the permits & inspection corners to save some time & $$ and didn't get caught. JackpineMoron "jwirr" tried to save some time & $$ and got caught. "jwirr" knew the risk, went ahead anyway, and now faces the consequences. I can't bring myself to sympathize.