Continuity mistake: When Mr Potter removes the stuff that the exterminator accidentally sprayed on his face, it's thicker than in the previous shot.
Continuity mistake: I don't know the breed of the exterminator's dog, but she's of a different one during one shot, when he finds her after she ate milk products in the factory.
Continuity mistake: Right after the vacuum incident, Homily Clock goes to give Arrietty a raisin and Cheerios. She walks up the stairs holding only that, yet when she reaches the top and enters her room, a cup of milk magically appears on the plate.
