Continuity mistake: When the drill sergeant spins Donald around, he crashes down and you can see there is a footprint in the ground behind him, but when we see Donald a few shots later, the footprint has disappeared.
Continuity mistake: When Daffy sees Dr Jerkyl's house, he is holding a telegram in his hand that disappears when we see him in the next shot.
Continuity mistake: When Bugs is holding the stick of dynamite in his left hand, he puts the other hand in his ear to avoid the explosion. You can see that Bugs is holding the stick with all of his fingers, but when we see a close-up of the stick in the next shot, he is holding it with only two fingers.
Continuity mistake: When Porky is about to put the pole down into the ground, you can see that there's nothing behind him, but in the next shot trees have suddenly appeared.
Factual error: The events depicted in the movie occur around the time of the California gold rush in 1848, yet every man and his dog wields an 1873 Colt Peacemaker.
Continuity mistake: When Elmer opens the door and finds Bugs at the dressing table in ladies' underwear, you can see the door is positioned on the left hand side of the frame. But when we see Bugs, the door is now on the right hand side.
Continuity mistake: When Reginald Owen who is a British agent posing as a German hits a German Captain on the head the German doesn't have a hat on.When he pushes the German out of the car when the body falls out it has a hat on. (01:31:45)
Continuity mistake: When Bugs puts a cigar in Ala Bahma's mouth at the end of the cartoon, the background is blue with a pink curtain, but after the cigar explodes, the background is green and the curtain is blue.
Revealing mistake: Inventor Dr.Tobel is shown with his bomb sight. Later in the film we see the same equipment, only this time it is Sherlock Holmes' ultraviolet light apparatus. (00:22:05 - 00:45:30)
Continuity mistake: Robert Cummings is talking to a Viennese doctor. The doctor lights a match for his pipe. Then, in the next shot, there is no match.
Continuity mistake: Near the end, as a plane is getting ready to run down the airstrip, Bogie knocks the gunman out, then uses the gun to shoot the plane in its tracks. When the machine gun starts to fire, it has a long strip of bullets, then fewer, and so on.
Continuity mistake: When we see Elmer reading his book at the beginning of the cartoon, the strap of his gun switches shoulders between shots.
Audio problem: When we see the moth singing on his way to the bar, his mouth doesn't move.