If you think about it, park rangers are usually people who enjoy the outdoors, and they see their job as encouraging visitors to enjoy places without damaging the environment. I'm sure they see their enemy as anyone who'd be careless or destructive, not someone who's taking a shower in a spot that turned out not to be very private. Probably no ranger sees dealing with conflicts between visitors as an enjoyable part of the job.
Police officers, on the other hand, often see themselves as guardians of law and order (and are seen as such by the public generally). Maybe they're judicious about this role and maybe they let it take over their personality. But a policeman is not a lawyer: most of the time they might recognize a crime, but there are times when they may not get the true meaning of the law, especially if what's commonly believed isn't exactly what the law says. I think that might be the case with public nudity, even in places where it's not definitely illegal. There's very often some vagueness in there--so in England and Wales, the offending action would be "Conduct likely to cause alarm and distress", and what does that mean, exactly?
I remember that case in Northern Ireland, but I don't know if the law there is the same as England; there are some differences. If it's the same, the policeman was entirely wrong, but he might have had the idea that "Anyone naked in public is guilty of indecent exposure, and it's a sex crime". In fact non-sexual nudity hasn't been treated that way in England for years. Davie (or anyone) do you know how that case turned out?
