Samantha's Thanksgiving to Remember - S4-E12
Visible crew/equipment: While Sam is defending Darrin during the trial, just as she mentions their absurd belief that if someone speaks differently it's a sign of witchery, the white chalk T-mark is visible on the floor under the desk, where Phineas is sitting. It was not there in previous shots. (00:19:25)
Answer: Larry had been telling Darrin what it means psychologically that Samantha gave the coat away. Larry said giving it away meant she's happy being married but if she liked the coat it means she desires to be single and carefree. So when Darrin sees the coat, he immediately thinks Samantha doesn't want to be married and the fact that she twitched it means (in his mind) she wants to be a single, carefree witch again.
Bishop73