Visible crew/equipment: During the flashmob, there are people walking toward the camera while dancing on the street. The shadow of the steadycam filming the scene is left of screen.
Plot hole: The spell Magicae Maxima works, but it shouldn't have worked at all because there was one ingredient missing, the petrified spider.
Factual error: In one scene, Winifred asks Gilbert who Trask is and Gilbert replies that Trask is the "mayor", to which Winifred just acknowledges. However, the office of mayor was not created in Massachusetts until 1823, which is 130 years after they were hanged, so given the witch's lack of knowledge of the modern day, she would have likely not known what Gilbert meant.
Visible crew/equipment: During the competition at the carnival, the original sisters lose, and the winners are celebrating. Bette Midler comes forward to interrupt their celebration. The shadow of the camera appears on her lower body.
Plot hole: The incantation for Magicae Maxima must be repeated 7 times without making a mistake, or they have to start over. Winnie says the spell wrong but the spell works anyways. The first time she says it (with Book), Winnie says "From North, the East, the South, the West," but the last time she says it (without Book), she says "From North, South, East and West" (not in the right order).