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: After the inflated bird is popped by the fly, it lands on what appears to be an ape's head and begins spinning around and tap dancing on its head. The ape has both eyes open and looks pissed as he keeps playing his cello. Before the camera cuts, the bird has spun slowly so it's back is to the camera and the ape still has both eyes open. Then it switches to a different shot as another animal is about to smack the bird with his cello, and suddenly the bird is facing the opposite direction, and the ape has one eye closed. (00:06:25)
Continuity mistake: When Mickey is knocking on the door of the haunted house, the door has two bottom panels, but when the door crashes to the floor, the panels are missing.
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.
Continuity mistake: When we see the animals change seats at the start of the cartoon, you can see there is an aisle in the middle of the theatre, but when the show begins in the next shot, the aisle has disappeared.
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.