Read their waivers. They do not "sign off". They never did. They never will. They require a professional stamp on the work... that is what they review... not the work, but the credentials of those RESPONSIBLE for the work.

Then, read contract law. As a third party, so called "inpsectors" have no liability under contract to other third parties. Even though they charge a fee, the fee is so minute that no liabilty can be attached (see above).

It's just common sense. If a building is built by a builder, his contracted parties for design and construction are his alone to sue if anything goes wrong... NOBODY else. Not even those injured. They must sue the builder, who, in turn, sues...

Read up on the law... I gotta cook supper.