Building standards are created when experts in each trade get together and do their best to agree on what is safe. Then they write it all down, numbering each provision so that different people can refer to them more easily.
When an inspector's comment is challenged, he can use those expert's opinion (a building code provision) to support his comment, or he can claim to be the expert in everything himself, which may not be accepted by a seller, their agent, or a contractor, and for a lot of inspectors that claim will get shot down pretty easily in court.
Just because an inspector refers to an expert opinion that supports his comment doesn't mean the scope of the inspection is expanded to include everything in the IRC or any other standard referenced. The scope is defined in the agreement, often in the report introduction... and to 1st time buyers, maybe verbally.
Of course, this can vary with jurisdictional regulations, but I think generally, it's logical.
I don't cite code provisions in my Narrative Library, but if a disagreement should arise, I wouldn't hesitate to cite one as support. Easy access to pretty much all building codes an inspector is likely to need are available on my website, and often provided in my templates, (depending on which software an inspector is using).