Other mistake: After the great fire scene there is a raccoon that drags her baby to shore and begins cleaning it. A few seconds later the baby has jumped across to the other side of his father and siblings, but the mother does not stop licking.
Continuity mistake: When Woody has the landing gear lowered on the burning airliner, only the right main gear comes down. When Pappy warns him that the other gear isn't down, he pulls up and goes around. As the camera pans over the plane, it shows the left gear down, and the right up. Then when Woody retracts the gear, once again the right one is down.
Factual error: This relates to the first movie with this title, the one with Jack Benny in it. About midway in the film there is a scene with Polish pilots in the RAF in a room. It cuts to a brief shot of airplanes flying which obviously purports to show the Polish pilots flying their airplanes. But, the airplanes shown are circa 1935 U. S. Army Air Corps Consolidated two place fighters, never used by the RAF and in fact totally obsolete and never used by any air force during WWII.
Visible crew/equipment: In the final musical number "Strictly off the Record", you can clearly see the shadow of the microphone boom during part of the number.
Revealing mistake: In the scene towards the beginning, when the Chinese mob are talking in the car junk yard, the Chinese guy about to be crushed to death is begging for mercy. While the Chinese mob are talking, when the camera pans to the guy about to be killed, you can clearly see that it's a dummy, then in the next shot it's the real guy again.
Factual error: When King Cutler shoots his brother near the end of the film, he uses a revolver, a weapon not produced until the next decade.