Seen at the bar

An older, balding, bespectacled man in a police jacket.  Were it an MI-5 jacket he could be straight from a Le Carre novel -- the middle-aged, middle class part of the security apparatus.   Behind the bar, he picked up each of the very many bottles and swirled it, then held a flashlight to the bottom, shining the light through so the bottle glowed.  Looking for cracks? Worms?  Sediment? Fingerprints?  In any case, a job for the police.