Continuity mistake: When Helga brings in Klink's dinner and sits it down, Klink takes off his monocle. In the close up, it's on and his hands are folded, then he points to a chess piece, contemplating a move. In the wide shot, he's holding his monocle, and puts it on.
Continuity mistake: Col Hogan eats Col Klink's chicken leg and places it back on the plate with meat still on the bone. When Col Klink picks up the chicken leg after, there is no meat on the bone. It's stripped bare. (00:01:00 - 00:03:00)
Continuity mistake: When Hogan drinks Klink's wine, he picks up the glass with his right hand and his left arm is behind him. A second later, Hogan's left hand is in front of his chest.
Answer: It's a comedy, not a documentary.
stiiggy
Perhaps it was counterfeit. There are numerous episodes where they deal in counterfeit monies.