When Daffy has his company's truck dump the appliances in Elmer's house and a great deal of noise is heard, part of the entryway can still be seen behind the truck, but nothing comes out of it.
When Daffy lowers the second floor to first floor level, we can see there is a useless outer door on the second floor.
When Daffy shows Elmer the "garbage disposal," he is supposed to say, "Regardez vous," but "vous" cannot be heard.