Special inspectors are required to report to the building official.
They are also required to furnish the RDP and building official copies of His/her reports.
A signed final report of work accepted is required as well (Certificate of Compliance). The building officials rely on the special inspectors as their "eyes and ears" on the jobsite.
Or, as mentioned above, verification inspection is performed when the owner gets off their wallets. This (IMHO) is the QA side as mentioned above as well.
There are good inspectors, and bad ones.
There are good building officials, and bad ones.
Many BO's rely completely on special inspection who are supposed to be qualified by testing or approved by the building department or jurisdiction. Many have told me they do not have a clue about our trade, they are not "know-all" individuals, they are overseer's.
I perform verification inspection regularly for engineers, architects and owners. I like this end of the business. I have to answer to the building depts. and satisfy the RDP and the owner who is watching the $$. Often verification inspection is not required, but a QA inspector is requested due to the nature of the project.
A couple of years ago while doing QA, the special inspector showed up 1/2 hour late w/bladder buster coffee and maple bar in hand, the contractor started an hour early. The engineer was with me and he was somewhat surprised at the state of his project. The inspector would not climb the pour pans as this was unsafe... I came up with a 2 page punch list vs. his 2 items. That is one of the checks and balances of special inspection.
There are some good special inspectors, but I do believe they are few and far between. I have a photo of one sleeping behind a building, others play golf, and then expect a paycheck at the end of the week.