Continuity mistake: When Porky realises he's been tricked at the Toll Bridge, he throws his gun in the snow, and when he runs off, you can see there is nothing in his hands. But when Porky arrives back at the Toll Bridge, he is holding his gun again.
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 Jerry goes to the door, you can see the telegram is by the letter box and after reading the telegram, he throws it away and jumps for joy. But when Jerry goes to show Tom the telegram, it is now back in its original position.
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.