I guess the police have their fair share misinformed people like any other segment of the population.
I recently got hassled at a local gun range by a policeman. The guy did not know what an AK pistol was. He asked me if I had any documentation to prove I could own an SBR. I politely told him that the weapon was a Draco AK pistol and was not an NFA item, that said weapon was imported into this country as a pistol (it does not have a stock on it) and that it was legally purchased via an FFL.
He walked off somewhat annoyed and confused by the answer. I hope he goes back to the station to verify what I said and I hope he now knows the difference.
What a dufus!