Factual error: As the train with Wilson aboard pulls into a town toward the end of the movie the year is 1919. Through the window of the train, looking out into the parking lot, there are two cars from the mid to late 1930s.
Continuity mistake: When Daffy says to Porky, "Did you lose something, Fat Stuff?" the number of trees in the background decreases between shots.
Continuity mistake: When Granny is speaking to Sylvester at the start of the cartoon, you can see there is nothing is under Sylvester. In the next shot, a green pillow appears, and in the shot after that, it has disappeared.
Continuity mistake: When Daffy flies into the squadron headquarters, you can see that the strap on the left-hand side of his helmet is resting on his arm, but in the next shot the strap is directly behind him.