Continuity mistake: Hogan and company use red painted gold bricks to replace the wooden stairs that they sabotaged. The steps after this episode should have been brick, but they went back to being wooden.
Continuity mistake: When Schultz comes out, he talks to the guard posted there. A moment later, the guard is gone.
Continuity mistake: After the POWs cut the stairs outside Col. Klink's office, Sgt. Schultz walks down them. There is a guard standing to his right. After a switch to show the POWs, when the camera goes back to the stairs, Col. Klink walks out and falls when the stairs collapse. The guard is missing without making any motion to move before. When everybody rushes to Col.Klink, the guard runs in from the left also.
Answer: It's a comedy, not a documentary.
stiiggy
Perhaps it was counterfeit. There are numerous episodes where they deal in counterfeit monies.