The Safe and Sane Halloween - S4-E8
Revealing mistake: In this episode when the Gremlin, Goblin, Jack-o-Lantern, and Sam are peeking in through the back window, the gremlin turns to look at Sam when she is speaking and his ear passes through the area where there is supposed to be glass.
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