Continuity mistake: When Sylvester is banging on the door of his apartment, there is no handle on the door. When his lady opens the door, a handle has appeared, and the door panels change.
Continuity mistake: When the orange cat attempts to escape with Tweety, he is hit in the face by an iron and slides back down the stairs. At this point, you can see the door to the exit is open, but when Tweety escapes a little later on, the door has gone.
More trivia for Putty Tat Trouble