Revealing mistake: After Holmes reveals that Mr. Potts is Ransom, the detective and the murderer have a conversation. After Holmes says 'No, not necessarily', the shot changes. In the next shot, you can see that the man standing in front of Basil Rathbone is not Gerald Hamer. This man has much less hair than Hamer and has a broader forehead. (01:10:39)
Revealing mistake: Several pieces of furniture, including a large sofa, fall over before the suitcase bomb actually explodes.
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: At the flight station, when the captain addresses his men and says, "That's 28 men and 28 tries," the captain's ribbons, medals, and cap change colors. (00:03:15)
Continuity mistake: When Spike is captured by the dog catcher at the end of the cartoon, you can see that there is a padlock on the door of the van, but when Jerry is chasing the van in the next shot, the padlock has disappeared.
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: The book Sniffles is reading is coloured green in long shots, yet in close ups it is yellow.
Continuity mistake: When we see Porky and Daffy sleeping at the start of the cartoon, you can see that the light above Porky's bed has nothing on it, but when Porky goes to bed later on, the light now has a cord attached to it.
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.