Sweating the joints would have taken maybe a minute more per joint -- a metal-metal bond is more reliable than rubber-to-copper. Leaving gaps in the cement around the vent pipe is just bad work and a CO hazard. Same with not supporting the expansion tank -- it's bad work, a leak hazard since it stresses the pipe joints, and takes a few minutes to do right.

The install would have flunked inspection as it was, and rightly so. Unfortunately, you have to wait a few weeks for an inspection appointment in that town.

Oh, and the kicker? They didn't re-open the water valve to the house fully. When I took a shower after I finished cleaning after them, there was next to no water pressure, and the pipes were making a screaming sound.