Happy Birthday, Dear Hogan - S4-E26
Plot hole: In the cinema, Hogan and his female underground contact avoid attention from a passing plain clothes policeman by kissing. This is wrong for three reasons. Firstly, 3rd Reich Germany wasn't so liberal that open kissing in the cinema would have passed as normal, it would probably rather have been viewed as libertine and offensive. Secondly, the scene takes place with a speech of Hitler as the background, which can hardly be viewed as romantic, and thirdly, this is even more true for the Gestapo, who was tasked with ratting out political dissent. To a Gestapo officer, ignoring the Führer's speech and kissing instead would make them stand out doubly.
Answer: It's a comedy, not a documentary.
stiiggy
Perhaps it was counterfeit. There are numerous episodes where they deal in counterfeit monies.