The first victim, Cheryl Ann Hughes, is described as possessing a brown belt in Karate. But when the vampire seizes her by the throat, she uses none of her alleged skills, even though (in Karate) this is one of easiest holds to break.
During the fight with Skorzeny at the swimming pool, when the police finally have him pinned down on the ground, they let go of him and one of the officers tells him to "get up...slowly." None of the officers attempt to put handcuffs on him, which they would have done immediately, especially with someone suspected of multiple murders.
In the fight in the swimming pool, everyone falls in with their shoes on. When they are shown underwater, everyone is in their stocking feet. When they come out of the water, they all have their shoes back on again.
Kolchak is called from Gail's apartment to go to a crime scene. He leaves the apartment wearing a shirt and sport coat. Driving to the crime scene, he has a necktie. When he arrives at the crime scene, his necktie has disappeared.
When Vincenzo tells Kolchak he won't print the vampire story, Kolchak suggests that instead they print a special featurette interviewing the two girl victims. There was a third female victim that happened before this scene.
When Kolchak and Jenks are talking at a table by the side of the pool, a blonde with an orange and black bathing suit walks by their table. A few seconds later, we see them speaking from a different camera angle, and the same blonde passes by, going in the same direction, and without enough time having elapsed to have walked around the entire pool already.
When the vampire is running away from the hospital, you can see a stunt man come to the aid of the motorcycle driver who lays down his bike. The stuntman is the same one who was fighting with Janos Skorzeny (the vampire) and was thrown out of the window.
When the vampire is in the hospital stealing from the blood bank, a nurse is thrown against a wall, and knocked unconscious. But as the scuffle continues, the "unconscious" nurse, moves her legs - twice - to avoid being stepped on.
At the construction site where the girl's body is found, Kolchak's car can be seen in the distant background, ready for the "cue" to come roaring forward. When he gets there, you can see the previous tire tracks where the scene has been rehearsed.
In the climactic showdown scene, when a weakened Skorzeny (Barry Atwater) is laying against the stairs he turns around to see Jenks holding the chrome cross close to his face. Apparently seeing his face in the reflection of the cross (and possibly being startled by his appearance), Atwater begins to laugh, and the camera quickly cuts away to another shot.