Columbo is looking for a weather report from last Tuesday, the 18th, but the March 1973 calendar prominently displayed in the wine laboratory shows the 18th as a Sunday.
When Adrian Carsini emerges from the wine cellar after moving the body, he is bare-handed, but seconds later, as he runs across to his brother's car, he is wearing snugly-fitted leather driving gloves.
When Columbo is explaining to Carsini how he solved the case, he lights a cigar, which he then removes from his mouth with his right hand. The shot changes to a close-up, in the middle of a line of dialogue so there is no delay, and he is now holding the cigar in his left hand and the book of matches in his right.
In the restaurant, Columbo lights a cigar at his table. The cigar is in his mouth when he draws on it, then looks up and smiles as Mr. Carsini and his assistant approach the table. The camera angle changes and the cigar is suddenly gone from his mouth as he greets the pair.
When Adrian is pouring wine, Columbo is unwrapping a cigar. Before looking up to see Columbo with his cigar, Adrian asks Columbo not to smoke.
When Columbo first appears at the crime scene by the ocean where Enrico Carsini's body was found, the cop who first talks to Columbo puts his hands all over Carsini's car which absolutely would never be tolerated at a crime scene investigation, especially one involving a potential murder.
The medical examiner fails to spot the discrepancy between the time of death and the amount of time spent in the water.
During the wine tour, the bottles on the assembly line are made for screw on caps, as found on bottles of very cheap wine at that time.
When Columbo is talking to the cop standing next to the victim's car, he declares that "it must have cost a year's salary". A very expensive sports car like that would have taken several years of a cop's salary to buy.
Although Rick's girlfriend tells Columbo that Rick's family is from Milan, Adrian calls his brother "an ignorant Neapolitan."
After 1 week, Ric's body looks as plum and healthy as when he was alive.
There is no news van and camera crew when Ric's body is brought up on a stretcher and yet the news broadcast shows images of the events.
When Columbo calls from the winery telephone, he dials directly, yet a sign immediately above it says to dial 3 for an outside line.
After dumping his brother in the ocean, Carsini fails to assemble his escape vehicle, the collapsible bicycle, correctly, locking the handlebars instead into an unusable position.
When Joan shows Columbo the letter she received in Mexico with the $5000 check, there are stamps and a name on the envelope, but no delivery or return addresses.
The wine that Carsini and Columbo drink at the conclusion is a white dessert wine. No white dessert wines are ever marketed in a fiaschi or straw-covered bottle.
At the dinner in the restaurant when the wine steward brings the port, it's already in the decanter. He soon offers the cork for Columbo to smell but just before that the sound of a popping cork is heard, which is wrong since the wine had already been uncorked and decanted.
While Columbo does have a few sips of wine in Adrian's office, it wasn't enough for him to feel dizzy when he stands up.
Adrian Carsini's car has no rear view mirror in the two-shot as he leaves the restaurant with Karen after dining with Lt. Columbo.
All the stunt with the overheated port proved is that the temperature in Carsini's wine room got so hot that it ruined his wine. It didn't prove Rick died there or was even in there, at all.
Adrian tells Columbo several times that it is a locked vault but there is no lock on the vault door, just a handle.
In the opening scene, the four wine connoisseurs hold their glass very properly but fail to swirl and smell the wine before drinking it.
A wine connoisseur like Adrian Carsini should certainly know how to pronounce "zinfandel" or "Amontillado".