"I don't know how rescues go in the national parks now. It used to be that they had an unofficial rule, that if the victim was 100% legal, with any necessary permit, doing something that was totally permissible, and then they had some very bad luck, that the rescue would happen for free. However, if they were doing something wrong, lacking any necessary permit, or somewhere where they shouldn't have been, that the rescue was billed to them.
That is part of the reason why there are so many rules at the national parks, just to help keep visitors out of trouble."
I never heard of this rule, unofficial or otherwise, at least in the way you have stated it. Charging for rescue costs is discretionary, and it is therefore a judgement call. Actually in many parks, the county sheriff will be the responsible party for conducting rescue and the county policies will apply.
Actually, this is just common sense. If you have shady characters doing bad things like poaching wildlife, pot hunting archaeological sites, digging up plants for profit (ginseng roots,for instance) would you be inclined to cut them any slack?
I am reminded of a private sector example. More than sixty years ago, some poachers decided to bag some elk on Santa Rosa Island (now part of Channel Islands NP), then a privately owned ranch,along with the elk which were reserved for guided (and quite lucrative) trophy hunts. These guys landed their plane ona remote ridge in theSE sector of the island, bagged their elk, and then found out that the ridge was not long enough to take off.
They had to walk to the ranch house and throw themselves on the ranchers' mercy, which actually was considerable in that they were not lynched on the spot. Maybe that was because Sanat Rosa Island does not have very many tall trees. In any event, they got no help in retrieving their plane and it remains to this day on a high barren ridge in the Sierra Pablo. You can probably spot it on a good aerial photo if you know where to look.
I am,of course, fairly biased, but I do think most (not all,surely) of the NPS regs can be justified, even when the rationale is not self evident.