In my experience, the person that controls the purse strings has a lot of influence.
I often see realty transactions where the underwriter for the lender that is issuing the loan to the buyer will "require" certain things be done, including, but not limited to, removal, repair or improvement of parts of a piece of property, before the monies are released to the lender.
The purse string holder has no "Code" standing, yet, in my opinion, can be as effective as the AHJ.
The history of the local Authority Having Jurisdiction is another matter to consider. Jurisdictions I have experience with have a catch-all phrase such as:
All electric outlets and fixtures shall be installed, maintained, and energized by a source of power in a manner complying with the Electrical Code applicable now or at the time such outlets or fixtures were, or are installed.
If the house described in the opening post is in a jurisdiction that has a history of continuous National Electrical Code enforcement through the life of the dwelling, it is highly unlikely that adding bathroom outlets to the small appliance circuits was ever compliant with the Code.
The home inspector, noting that the bath outlets are connected to the small appliance circuit, should rightly make note of such. I, for one, would be curious to know how the circuits are spliced together, and would question the workmanship involved. This smacks of a DIY hack.
Caveat Emptor.