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.
Continuity mistake: Hunky takes off chasing the truck that took Spunky and tries to save him, but then trips and slides on his face and belly on the ground, coming to a stop. There is a large rock beside him. When the camera changes angles, the rocks design changes significantly. (00:01:40)
Continuity mistake: When Elmer thinks he's going mad, we see a close-up of the book "How to Photograph Wild Life" and you can see there is damage to the front cover and the spine. But when the rabbit throws the book at Elmer at the end of the cartoon, there is now no damage to the book at all.
Continuity mistake: When Elmer thinks he has captured Bugs in his trap, there is a sign by the trap that reads "Carrots." In the next shot, the sign has gone.
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: 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.