Continuity mistake: When Ron Moody runs into the sea in pursuit of a suspect trying to escape, he shouts at Jessica to "Get the package!" In the next shot we see Jessica reluctantly follow him in, with a clear waterline from a previous take showing on her dark overcoat/cloak.
Continuity mistake: The pad where the knife is stabbed protrudes under the writer's shirt.
Continuity mistake: When Jessica limps into Milton's car, she holds onto the door. A shot later, her hand is away, and it's Milton's hand instead holding onto the door.
Continuity mistake: When Jessica (a stunt double) is knocked down, her left arm is under her body with her bag in front. An instant cut later (now Angela Lansbury), her arm and bag are behind her back.
Continuity mistake: When Milton picks up Jessica at the airport, her bag is hanging over her right shoulder. A shot later, she is holding it with her left hand.
Funeral at Fifty-Mile - S1-E22
Continuity mistake: When Jessica walks from the house to the barn at the end, she is wearing knee high brown boots. By the time she reaches the barn they have been replaced with court shoes.
Funeral at Fifty-Mile - S1-E22
Continuity mistake: Carl arrives at the funeral in his RV and then heads to the house. When he arrives, it's a noticeably different model. The door's moved, the front right window is now segmented, and rails have appeared on the roof.
