Samantha's Hot Bed Warmer (2) - S7-E4
Continuity mistake: In the opening scene, Samantha's purse is on the couch. It is initially lying flat with handles up on the back of the couch. When the officers are let into the room, the purse position changes. It is now standing upright.
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