Pifias

The helicopter in the night patrol switches between two distinctly different makes and models. When Deputy Commissioner Mark Halperin goes on helicopter patrol, his helicopter actually changes type twice during the flight. First seen is a Bell 206 JetRanger, which then turns into a Hughes 369 before reverting back to the Bell 206. Commissioner Halperin is then seen climbing out of the Hughes 369 to drag his wife's body out of the pool. The two helicopters are very different, even to the untrained eye.

When Columbo is interrogating Hugh Caldwell in his backyard, the small side gate (through which Halperin broke into his house the night before) changes from closed to open almost every time the scene alternates. Also, although Columbo's car is parked right outside this gate, he leaves the house by the front door instead of going through it.

After Columbo checks the tub and notices that it is clean and dry he is speaking with the other Lieutenant (played by John Finnegan) and he refers to the murder last night and he was referring to Janice Caldwell. But they've already had her funeral.

The position of the (broken) windscreen wipers when Columbo arrives in the rain at car dealer changes.

When Columbo's car refuses to start at the victim's house, he has a smoking cigar in his mouth, but during a brief closeup of him at his car, it's not there.

A gentle push down on a dead person's upper eyelids can never close the eyes permanently. Healthcare providers usually tape the eyes shut in the hope the eyelids will stay closed.

John Finnegan plays Lt. Duffy and is called by that name several times. However, the end credits list him as Lt. Dreyer.

The Commissioner's wife was in the water no more than ten seconds which is not long enough to drown.

The coroner misspoke. It is possible to determine the type of water a person drowns in. And they would find bath soap.

Even though there are 2 distinctly different helicopters seen, the sound of both is that of a Bell 206 JetRanger with a 2-bladed main rotor. The Hughes 369 makes quite a different sound because it has either a 4-bladed or 5-bladed main rotor.

Browsing through different police files of suspected known burglars in an attempt to identify Caldwell's blackmailer, commissioner Halperin did not recognize Artie Jessup by his file photo. Halperin knew the name of the suspect as "Artie Jessup", saw it on the folder, and looked at his picture and address inside. Artie Jessup revealed who he was to Mr.Caldwell when he told him "nobody makes Artie Jessup a patsy" in the bar. Mr. Caldwell simply gave the name to deputy Commissioner Halperin.

After arguing with his wife at the bar, Artie Jessup (Val Avery) goes to the pool table to shoot nine ball, but he places the balls in the rack incorrectly. However, he's not interested in playing an actual game of 9-ball, but just wants to waste some time by himself while waiting for his friend to show up. There's no need to arranged the balls correctly.

Dr. MacMurray (Joshua Bryant) first appears with Commissioner Halperin after his wife's murder, reminding him to take the pills he prescribed for him. A few minutes later, as the body is taken away, Columbo asks him to check for a few things in the autopsy. A personal physician and a coroner?

Although unethical, it is possible that the coroner, seeing his colleague in distress, prescribed some medication for him.

(at around 30 mins) Columbo is talking to Margaret who cut her jacket picking flowers. She is wearing an apricot shirt with a matching apricot ascot. However, depending on the TV calibration and the frames in the scene, both appear to change from a solid apricot color to apricot with very small white lines creating a squares pattern. This is particularly noticeable when she goes back to her house, right after Columbo calls out to her "and one more thing!". It seems like a continuity mishap but is more of a lighting goof, which makes the garments' pattern disappear, distracting from the scene at certain points.

Mark Halperin (played by Richard Kiley) addresses Amos Lawrence (played by Byron Morrow) as "Byron".

When Mark Halpern was inspecting Mrs. Caldwell's corpse her eyelids could be seen moving.

Provided the bathtub murder of the commissioner's wife is in real time, it seems impossible that she drowns within 2 seconds. That is the time it takes for the murderer to look satisfied. Drowning seems a little more complicated than that.

In the deputy chief's bedroom (after the murder of his wife), a bit of studio ceiling can be seen twice.

When Margaret is pulled out of the pool, the face of the stuntman in her clothes is plainly visible.

One of the officers tells Columbo that the diamond ring is fake and that a professional jewel thief would spot it instantly. That seems unlikely in the heat of a robbery and murder. Furthermore, in the bar, Artie has to examine the diamond with a jeweler"s loupe before declaring it to be fake.

Caldwell enters the bar and immediately approaches Artie sitting at the bar despite never having seen him before. He starts talking to him about the blackmail without ever verifying his identity.

When Commissioner Halperin peruses Artie Jessup's police file, Jessup's home address is listed in its entirety as "874 South Central Ave. L.A." Halperin goes to that address - an apartment building - intending to plant evidence to frame Jessup. Halperin walks through the front door, heads up the stairs and goes to unit 13 - even though the report didn't list Jessup's room number. (Halperin doesn't even bother to check the mailboxes.)

(at around 41 mins) Mark Halperin (Richard Kiley) refers to the murder plot as a "Quid Quo Pro" instead of as a Quid Pro Quo.

When discussing the car mileage with Columbo, the car salesman refers to the speedometer instead of the odometer.

When Columbo is talking to the medical examiner on his car radio, both parties treat the radio as if it's a telephone. In a real radio conversation, each party must say "over" then release the microphone button so that the other party can be heard.

Furthermore, names would not be given.