Columbo complains to Wesley that he has a "sensitive tooth on the left", as he chews his bagel on the right and holds his hand to his painful jaw - on the left. But when Columbo goes to the dentist, the dental work is done to a tooth on his right. And afterward, at the outdoor café, Columbo holds his hand to his painful jaw - on the right.
When Wesley injects Adam to remove his crown he injects the right side of his mouth but removes the crown from the left.
When Wesley Corman starts working on Adam Evans, he doesn't use a saliva suction device; however, in next shot, Adam has device in left corner of mouth.
When Columbo explains his suspicions to the dentist at the race track, the dentist orders Columbo a Scotch. Just as they part, the glass of Scotch changes positions between Columbo's hands and the little table a few times.
The coroner tells Columbo that he found a new gash on the victims right cheek, but proceeds to show him the left cheek.
Dr. Gorman claims he knew nothing about a patient's heart condition because he's a dentist, not an M.D. A dentist is required to take a patient's full medical history before treating them, therefore would certainly know about a heart condition.
When Columbo and the sergeant uncover the face of the deceased Adam Evans on the stretcher at the crash scene, Evans' eyelids flicker slightly.
In all cases of dentists working on patients, the dentists do not wear masks, which is a serious lack of hygiene.
As Columbo exits the red Mustang at the crime scene, the reflection of a large bright studio light can be seen the vehicle's left rear quarter panel.
When Adam's Mustang goes over the embankment, a cable can be seen attached to the rear.