After smoking a cigar with a BPD guy who is about to retire, I discovered that this doesn't really matter much- at least with regards to the whole "does the guy have a permit?" thing. He explained that he's not in the business of rustling people merely carrying guns (he's pretty pro 2A himself) but that if he wanted to get someone to produce a permit whom "he suspected of having a gun that wasn't supposed to" there is basically a way he can socially engineer people into doing it without violating the procedurals- "there are creative ways that you can ask to see their permit without acctually coming right out and asking them or demanding it from them". Not to mention even if the PD pulls a bogus search 9 out of 10 times it will escape scrutiny because of some other excuse. To get a court to block something because of a full blown 4A violation it has to be blatant- and you have to have an attorney that actually cares enough to harp on it.
-Mike