Factual error: The guard outside Klink's office and the two Gestapo soldiers guarding the gold truck have MP38/40 and a Thompson submachine gun, but carry rifle ammunition pouches instead of the long ammo pouches that carried the 30-round magazines used by the MP38/40.
Factual error: When the men are lined up to take the strongboxes of gold to switch with bricks, each man in line easily hefts and tosses them to the next man. Gold bricks weigh over 27.5 pounds (12.4kg) apiece. If there 10 bricks per box (going by the size of the boxes), then that comes to 275 pounds per box, plus the weight of the box, which these guys are tossing around without a problem.
Answer: It's a comedy, not a documentary.
stiiggy
Perhaps it was counterfeit. There are numerous episodes where they deal in counterfeit monies.