Continuity mistake: When Hubie and Bertie hit Claude's feet with a hammer, Claude eats them up. When Claude believes he is doing something wrong, he spits the mice out but the hammer is nowhere to be seen.
Continuity mistake: When Claude is reading the book near the book shelf, he has two fingers on the back cover. But in a close-up of the book, there are now three fingers on the back cover.
Continuity mistake: When Hubie and Bertie first approach Claude, you can see that Claude is sleeping by a dark maroon chair. When Claude is in the bathroom and says "I must be dreaming", we return to the chair and there is now an end table occupying the floor space where Claude had been sleeping.
Continuity mistake: When we first see the cheese where Hubie and Bertie have been eating from, there are two holes and by the left hole there are pieces of cheese. When Hubie emerges from the hole, the pieces have disappeared.
