Goofs

When Columbo is turning on the music that supposedly had been playing just before the phantom murders entered, he takes out his handkerchief so as not to get his fingerprints on the dial. Then when he sits down, the handkerchief disappears.

As Columbo questions Nadia the day after the murder, he lights his cigar with Dr. Collier's lighter. He then holds his cigar and his notebook in his right hand. As Dr. Collier crosses from the sofa to a chair, Columbo transfers his notebook to his left hand, at which point his cigar completely disappears.

When Columbo is talking to Dr. Collier in the computer room, Columbo's arms are in different positions depending on the angle of the shot. When seen from the front, both of his arms are lowered, but when the camera angle changes to view Columbo from his rear right side, his left arm is laying across his stomach, and his right arm is bent at the elbow with his hand up by his chin. This happens about 3 separate times during camera angle changes.

Dr. Borden explains to a visitor that laboratory mice are being tested to learn a new route in a maze. This requires that the mouse be able to distinguish between a red line and a green line. Mice are not able to distinguish red from green.

In the beginning, when Dr. Collier removes the IV needle from Nadia's arm, he lifts the bandage and puts a cotton ball on her arm. He doesn't act as if he's removing the needle, and the tubing just comes off with the bandage.

The interiors of the Van Wyck house in Playback (1975) and the Donner beach house in this episode are the same. Both have steps leading down from one room into two adjacent rooms at 90 degrees from each other. The door to the house enters at this upper level in "Playback", but the door appears to be covered up by a piece of furniture in this show. The fireplace is in the same location.

After Nadia jumps off of her balcony and Columbo goes there to investigate, Hendricks says the only thing that they, the police, have touched is the phone. Hendricks says the phone was off of the hook and was making a noise, so he placed the handset back in the cradle. But in actuality, the phone will only make that noise for a short while, then it goes silent if the owner does not place the handset back in the cradle..

There was a blind witness present when the murderer's car hit a column. Surely the car was damaged and either material from the bumper smeared on the column or material from the column smeared on the bumper, but the police failed to check for any such evidence.

The police cars don't worry about parking up the driveway before the "lab guys" arrive and contaminate the crime scene with new tire tracks.

Collier brags he has good medical training and yet he fails to first check if the victim is conscious, then breathing, then would normally check a carotid artery (neck) and not a radial (wrist) pulse.

When Nadia jumps from the window, she believes that she is diving into a swimming pool. However, she screams as she jumps. She wouldn't scream if she thought (under hypnosis) that she were only diving into a swimming pool.