Continuity mistake: When the seven dwarves run scared down the stairs and out of the door, Dopey pulls the handle of the door from the inside until it breaks out and falls away. The next scene when the dwarf opens the door, the handle is there again. (00:33:00)
Continuity mistake: When the goose is in the projection room towards the end of the cartoon, he pushes the leaver forward on the film speed and it is between "Slow" and "Fast." After we see what has happened to the film, we cut back to the projection room and the leaver is now between "Slow" and "Med."
Continuity mistake: When Porky arrives home, you can see a window looking outside to the right of the front door, but when Porky shoots the man upstairs a second time, the front door now leads to a hallway with a staircase.
Continuity mistake: When lawyer Goodwill is in the secret laboratory, he picks up a bottle that has "Jekyll and Hyde Juice" written on the label, but when we see him with the bottle in the next shot, the words have disappeared.