I ask them about it. If they show me a CCP, I say thank you and have a nice day. if they don't, they go to jail. It's a privilege to carry concealed, not a right - so if LE asks about it, don't give them any grief.
here in the law does it say we must show you our CCP? I think you are incorrect sir. Simply seeing a gun print does NOT entitle you to stop the citizen and "investigate". The ONLY times you are allowed to act in such a manner is when you have REASONABLE SUSPICION or PROBABLE CAUSE. You have to be able to articulate it in court too. "ah, judge, I saw him print, so I searched him" will NOT fly.
Read post #19 by loadnplenty, I think he is 100% correct in how he handles it. In the OP story there was a 911 call and the guy admitted to not having a permit. I feel there was reasonable suspicion and the officer can articulate it in court. "we got a 911 call, I saw a guy with an exposed firearm in a convenience store" It would be even better for the LEO if the store had been robbed before and if it was late at night but the story doesn't say.