Witches and Warlocks are My Favorite Things - S3-E3
Other mistake: The exterior scene when Clara parachutes in is not the real outside we see throughout the show with neighbors including the Kravitz across the street and fewer trees...and no pine forest. Also, it's obvious Marion Lorne, who was about 80 at the time, was sitting on a swing like apparatus being lowered... understandably.
The Short, Happy Circuit of Aunt Clara - S3-E9
Other mistake: When Louise returns, when the cow is in the living room, she says Samantha has given her the "wrong jacket." When she leaves again, she takes the same green jacket with her.
Other mistake: When Samantha and Clara "pop" into town searching for Ben, they appear on the sidewalk a few feet in front of others, who don't react to their sudden, magical, appearance.
Other mistake: In the opening scene, Endora disappears then reappears for Tabitha. If you watch closely, just before she reappears you can see the shadow of Agnes Morehead/Endora on the wall behind the couch quickly coming back to the couch for the camera cut to recapture her.
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