Best movie mistakes of 1941
Continuity mistake: When Lou is finally convinced that he won't get hurt being the umpire in the "Hit The Umpire" game, he runs to take his place then stops in front of the batter. As Lou runs to take his place he isn't wearing a baseball cap, nor is he holding one in his hands, but in the next shot, when he gets hit in the head by the batter, one has mysteriously appeared on his head.
Continuity mistake: Early in the film, when the gypsy Bela becomes a wolf that attacks Jenny and bites Talbot, he is in true four-legged animal form, sans clothing. After being killed, his human corpse is wearing clothes although it is remarked that his feet are bare. Later, when Talbot transforms, he is a Wolf-Man, wearing clothes and walking on two legs.
Factual error: As the beginning shows Krypton explode, there is a huge cloud of dust at the remains of the planet that then fades to nothing. Only space dust would not act like that from an entire planet exploding. It acted like dust settling on the ground and just fading away, rather than dissipating into space.
Factual error: Abbott and Costello have inadvertently enlisted in the Army but anyone weighing 240 pounds or more will be rejected. When Costello steps on the scale, the Army physician tells him, "You're in the Army. You made it by two ounces." Medical scales at that time (1941) showed weight in whole pounds only and did not show ounces.
Audio problem: Right at the beginning, a man is using a horse to plough a field, and behind him is a little girl, who finds an old doll that has been churned up by the plough. The little girl says,"Grandpa, look what I found." Grandpa and the horse stop working, but then he says, "Whoa, Nellie," to the horse, which has already been stopped for a while.
Visible crew/equipment: After the moving candle/ghost incident involving Ferdie and Camille, and before Moose Matson's money is discovered, Chuck and the doctor come running in, and they all start yelling and talking, there is a person (probably a crew member) briefly visible in the round window in the door in the background.