YES! you would not be cited because you are not in NAS! Inside a building/enclosed structure is guess what, inside a structure. You wouldn't need a permit, registration, authorization, part 107, or a TRUST cert to fly inside. Say you own a sports arena with a closed top, no need to register your drone. Once you open the top, the rules change (thinking Silverdome style). Because as you say, there is no danger to manned aircraft inside a building.
Because interiors are not navigable airspace, they are not maintained, controlled or regulated by the FAA. So in reality, this argument doesn't matter, as it isn't what the thread is about.