Continuity mistake: When Daffy raises the upstairs to show everything downstairs has been destroyed, you can see there is a crushed table next to the elevator. The table disappears in the next shot, and in the shot after that, it is back again.
Continuity mistake: When Elmer decides to have a go on the main control panel, you can see there are no words in the boxes above the buttons, but when he pushes the "Burglar Alarm" button, words have appeared.
Continuity mistake: When Elmer returns to his house after being given a lift back, you can see there is nothing on the front door, but when Elmer walks to the door in the next shot, a handle and a key hole have appeared.
Continuity mistake: When Daffy pushes a button to start the massaging chair, you can see that the button panel is on the arm of the chair, but when we see Elmer receiving a massage, the panel has disappeared.