I was stopped for speeding a couple of years ago... I deserved it.
During the interaction, I disclosed that I had a CCW permit and that my gun was under my driver's seat. I volunteered my CCW permit. The officer instructed me to leave the gun where it was and went back to his car to process my information. When he returned, he informed me that I was lucky he was a nice guy because he could be arresting me for a "weapons violation" because my CCW permit was no good. He said that because it was signed by the previous Sheriff, it was no longer valid. I told him that was ridiculous and that's not the way things worked. He was persistent. I then told him that it's a good thing Colorado law specifically allows me to carry in my car. He told me there was no such law.
He didn't arrest me, but he was confident enough in his assertion that I called a buddy who teaches CCW classes. I also called the Larimer County Sheriff's office to confirm the validity of my permit. In hindsight, I almost wish he would have arrested me! That would have made a helluva story!
I'm far from being a LEO basher, but, as with any profession, there are a few bad apples.
RWW