When the aunts are stirring the cauldron at the beginning of the episode, their spoons keep changing between them.
The quiz master takes bites of candy corn and puts them back in the bowl when he's talking to Sabrina at the end of the episode.
When Sabrina's aunts leave the room with the talking chairs, the little chair on the left moves causing Sabrina to sit down and you can see the puppeteer sitting on the floor behind the chair.