Character mistake: During the dancing girl scene, as they are singing the praises of Kane, the girl to the immediate right sings out of time with the rest of the dancers during the line "His favorite son." Even though she forgets to sing the line, she can be heard singing it a bit too late. (00:41:00)
Revealing mistake: When the elephants are making fun of Dumbo in the train caboose, Dumbo's mother pulls a pin which causes the stall door above the other elephants to fall. When the door bounces back up, you can see that the animators forgot to draw the elephants' heads and trunks and only their bodies are visible.
Revealing mistake: When the notice of impending strike is posted in the town, the American spelling of "labor" is used. A Welsh signwriter would have spelt it "labour."
Continuity mistake: When Larry is taken home after being bitten by the werewolf, the door opens and Larry is seen staggering in. In the next shot, the door is seen opening again.
Continuity mistake: When Jerry appears from the hair of the toy lion, you can see that behind him there is a decoration and some purple baubles. In the next shot, the decoration has disappeared and the baubles are now much closer to the lion.
Continuity mistake: Regina enters the house and places her umbrella in the corner. As she speaks to her husband, she first removes her right glove then her left. In the next shot, she turns toward the camera and removes her left glove again. (01:27:05)
Continuity mistake: Higgins hands mister J.P. Merrick the card from the Personnel head of the department store. Charles Coburn is holding it with both hands, which in close-up becomes just the right hand. (00:07:00)
Continuity mistake: When Alvin comes home in the morning his mother tosses a pail of water at him and not much of it touches his hair. Within a second or 2 the scene switches back and now his head is drenched.