In the "London 1912" segment of the film when Janet goes to pick up the will from the floor, her left hand is clawed by a cat, but when she jumps back it is her right hand that is cut and bleeding.
Towards the end of the "Quebec Province 1975" segment of the film when Lucy's knowledge of witchcraft has been revealed, the now-mouse-sized Angela pleads for Lucy to spare her life. She then holds her arms over her head, obviously to protect her from getting stepped on, but it is several seconds later before Lucy's foot is seen lifting off the floor to do so.
In the "Quebec Province 1975" segment in the film when Angela is flying her small remote-controlled model airplane, the shot cuts back to her operating the remote controls; however, in the foreground the tail fin of the airplane in front of her is briefly seen, even though it is meant to be flying around about 100 yards away at the time.
In "London 1912" the room where the old lady was killed had been trashed by the cats, when her nephew enters it is totally clean.
As a cat chews on a rope, shot to shot, small strips of meat can be seen laying on it.
In the "Hollywood 1936" segment of the film, Edina says "I tawt I taw a puddy tat!" quoting the famous catchphrase of Tweety, but Tweety would not be introduced in an animated cartoon until 1942, six years after this story takes place.
In the "Hollywood 1936" segment of the film, Edina is seen reading a Tarzan comic book that was actually released in the 1970s (the art by John Buscema is quite distinctive).
In the "Quebec Province 1975" segment of the film, Angela crashes her small remote-controlled model airplane into the front of her house where it explodes, yet her parents in the house never seem to notice.
In the "Quebec Province 1975" segment of the film when Lucy comes inside after Angela's small remote-controlled model airplane crashes into the front of her house and explodes, Angela tells her mother that Lucy fell in the mud while trying to catch the cat. In reality there was no struggle or mud, even though the mother says for Lucy to change into clean clothes and clean herself up.