Other mistake: In the intro to the Pastoral Symphony, the narrator identifies the deity who cloaks the world with Night to be Morpheus, who is the Greek god of sleep and dreams. However, the character in the animation is fairly obviously female, with long hair, eye shadow, and lipstick. My theory is that the character was intended by the art team to be Nyx, the Greek goddess of Night. Night would be a more likely candidate to be making it nighttime across the world, while Morpheus would be more likely to put people to sleep or send them dreams.
Suggested correction: Without further evidence/proof, this theory remains just that. A theory.
Continuity mistake: When Pinocchio is locked up in the cage of Stromboli, Jiminy goes inside the cage lock, and he hangs his coat and hat on the outside of the lock. In the next shot, they have disappeared.
Continuity mistake: Elmer is standing by a hole when Bugs is hopping around, but when he tells the audience that this fellow is a "RABBIT", we cut back to Elmer and the hole has gone.
Continuity mistake: When Donald Duck says "Uh-ho" when he is on the bear, the background behind him is sky but in the next shot changes to a forest.
Continuity mistake: After Mickey hides Pluto in his suitcase in Burbank, Mickey picks up his cane and runs to the train, then when Mickey actually jumps onto the train caboose he's only carrying his suitcase, he does not have his cane, nor does he have Pluto's suitcase (which had been filled with bones) with him. The cane reappears on the train later, and at the end Pluto's suitcase mysteriously reappears when Pete throws it at the duo in Pomona.
Continuity mistake: After the mouse is revived by water from Jasper, he goes up to the cat and you can see that the mouse's left hand is under Jasper's mouth, but in the next shot his hand is now near the whisker area.
Continuity mistake: When Papa Bear is drinking from the hot water tap after eating the hot porridge, the tap handle changes position between shots.
Continuity mistake: When Porky is searching for his contract in the waste-paper basket in Leon Schlesinger's office, he leaves some paper on the floor. But when Leon tells him to go back to work, we cut to Porky and the paper has gone.
Continuity mistake: When Elmer captures the rabbit in his net, the background behind the rabbit changes between shots.