The Flame Grows Higher - S1-E31
Visible crew/equipment: Toward the end of the episode, after the two women are taken out by the Gestapo, Shultz, Hogan, Lebeau, and Newkirk are standing having a drink. The camera goes in for a close-up on Shultz, there is a noticeable shadow of the camera on Shultz's coat, and right arm.
The Flame Grows Higher - S1-E31
Revealing mistake: As Hogan, Le Beau, and Newkirk help Schultz up the slope to the "forest fire", there is lumber stacked across a low spot in the top of the bank and covered with "snow" and grass. Probably meant as a path.
The Flame Grows Higher - S1-E31
Continuity mistake: At the end, as Schultz and Hogan come out of the office, there is a blank wall, like a kind of foyer. Any shots of the front door from the inside show the door opens directly into the outer office of the secretary.
Answer: It's a comedy, not a documentary.
stiiggy
Perhaps it was counterfeit. There are numerous episodes where they deal in counterfeit monies.