In the scene in the beginning of the movie, when the couple is driving around before they get to the cemetery, it's supposed to be night, but in the shots where we see the car from a distance, it's daylight, while it's dark in the close-up shots.
Ghoulita's position changes several times, from standing next to the grave, to sitting next to the Emperor.
Ghoulita's face and chest are a pasty white, yet throughout most of the movie, her hands and arms are a healthy flesh tone.
Shirley is secured to a post with her hands behind her back, but the top button on her blouse alternates from being buttoned to unbuttoned.
When the werewolf raises his head and howls you can see the skin of the actor's neck.
Shirley's hands are never tied securely from the time Ghoulita first threatens her - each time we see her afterward, she's just holding her hands behind the post, but they are not tied together.
During his struggle with the wolfman and the mummy, Bob receives a "mark" on his forehead that matches the paint used to paint the posts he and Shirley are tied to. This mark remains on his forehead throughout the movie.