Several times in the film, Eva Oster is called Mrs. Olson. Virginia Christine played a character named Mrs. Olson
in several TV commercials for Folgers Coffee.
When Dracula walks down the silver mine shaft with a torch, the torchlight shines on the other side of him.
At the end of the film, Billy fires seven shots at Dracula. All revolvers only hold a maximum of six bullets.
In the film, Billy the Kid holsters his gun on his right side and shoots right-handed. In real life Henry McCarty, a.k.a. William Bonney, a.k.a. Billy the Kid, was left-handed.
The wolfs-bane prop used in the film looks absolutely nothing like the real plant, which has blue flowers.
Dracula walks around in the daytime in several scenes in this film. In Bram's Stoker's novel, the main source of Dracula lore in these kind of films, sunlight takes away Dracula's supernatural powers such as changing into a bat or a wolf, but it does not take away his immunity to normal weapons nor it does kill him by causing him to disintegrate into dust.
At the end of the film, Billy the Kid shoots Dracula seven times. When that does not work, he throws the gun at Dracula. The prop gun apparently hit John Carradine's stunt double by surprise, right in the face, because he yelps in pain in a way that a bulletproof vampire probably would not do.
When the bat flies down to the stagecoach in the film, the prop operator controlling the descending mechanical bat is visible through the stagecoach's windows.
At the end of the film, Dracula is killed by a silver scalpel that is stabbed through his heart. Traditional vampire lore in Bram Stoker's original novel says that Dracula must be killed by an iron stake. Most vampire films use wooden stakes, which are easier for actors to handle.
In the film, Dracula does not have a coffin to sleep in when he is picked up by the stagecoach and he never has one in the house after he moves in with Betty as her uncle, James Underhill. The silver mine where he takes Betty to make her his vampire bride has a bed set up in it, but vampires do not sleep in beds.