Revealing mistake: When Missy steps out the "front door" to call George into the house you can see the backdrop touching the floor. (00:03:50 - 00:05:30)
Such a Nice Little Man - S3-E29
Continuity mistake: Hazel gets a glass to pour some milk. Hazel picks up the milk bottle in her left hand and begins to fill the glass from the left. In the next shot the glass is empty and a hand is shown pouring the milk into the glass from the right. (00:02:00)