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.