They have to be master plumbers to work in the city so how much should the inspector even need to catch? I've met third party inspectors over the years and I'd say generally they tend to follow the book more and the buddy system less. If you get my drift...

I tend to agree with your view. The same policy has been in place for HVAC people when it comes to installing new heating systems. Maybe I'm wrong, but it seems like a major plumbing problem will not result in death and will most likely be corrected.