The movie Grace Wheeler watches is a real movie Janet Leigh made for Universal in 1953 called Walking My Baby Back Home. It co-starred Donald O'Connor and Buddy Hackett.
When Johny Carson says goodnight, he says have a good weekend (meaning it is Frday). Yet the next day it is mentioned that it is Friday(n for her voice lesson).
Columbo's case rests on the fact that Miss Wheeler can't explain what she did during the 15 minutes extra running time after the film broke. However neither he nor Mr Diamond (who's desperate to find an excuse for her) suggest the possibility that she simply fell asleep before the film broke, waking up 15 minutes later.
When Elizabeth is shot in the video playback, the killer supposedly shoots her from off-screen to the right side of the screen. However, the puff of smoke comes from the left side of the screen.
Martha Scott is clearly breathing as the killer steps over her corpse and leaves the manor.
Trivia: For the first time, Columbo fires a gun. However he doesn't aim at someone, it's just to prove a theory about the doors.
After the "accident," Cadet Morgan tells Rumford that all the cadets are in the chapel, as ordered. A few minutes later, we see a group of cadets walking beside a building.
Columbo must wait for what seems like an eternity while the computer prints out the information he requested on Lewis Lacey. Finally, the computer stops. The last line printed on the form is "MORE?".
Columbo's last line said that Janus's confession was going to hang him. At that time, California used the gas chamber.
When Milo Janus starts the movie for his party guests, the take-up reel holds about two-thirds of the movie, while the supply reel (front) only one-third. In other words, the movie is already about two-thirds finished.
Furthermore, he had earlier mentioned to Buddy that this was going to be an "uncut X rated" film. The one being shown does not even remotely resemble that kind of film. The group he has over does not appear to be the type to watch that type of film either.
In the opening sequence, Milo's secretary (Gretchen Corbett) is supposed to be recording an incoming telephone call, but doesn't depress the record button (small red button) on the tape recorder. Technically, the tape recorder is in playback mode.
When Columbo is speaking with Milo Janus in his office after he's been doing exercise his track suit is all sweaty, but when they meet in the corridor a moment later it is clean.
Although the end credits tell us that actor Byron Morrow plays "Amos Lawrence", he is addressed on-screen as "Byron" by the Richard Kiley character. Also, although John Finnegan plays Lt. Duffy of the Robbery Division, and the character is referred to by this name several times, the end credits refer to him as "Lt. Dreyer."
Columbo is suggesting to publisher Riley Greenleaf (Jack Cassidy) that he might try his hand at writing. He refers to "a guy down at the department, -wrote a couple o' books, -maybe you heard o' him, -what's his name?". This reference, of course, is to Joseph Wambaugh, who by the time this episode was shot had written the novels "The New Centurions" and "The Blue Knight". Wambaugh would go on to write many more novels, including "The Choirboys" and "The Onion Field."
The techinique of using subliminal cuts would not have worked as shown in this episode since the audience would be aware of individual frames spliced into a film. In the original experiment, conducted by James Vicary in 1957, a tachistoscope (specialized and separate projector) was used, projecting a message for an interval of only 1/3000th of a second; such a brief period that only the subconscious mind could be aware of it.
At the beginning of the episode, Adrian has an open bottle of wine on his desk, allowing it to "breathe." After the little matter of slugging his brother, he fetches the bottle in and has his friend decant it. Later, with Columbo present, he states that he needs to open a bottle of wine so that it can breathe, but he immediately decants it and puts the stopple in, which would keep it from breathing.
Very Miles plays Viveca but in a scene with Martin Sheen in his house he calls her Vivian.
At the closing scene, the garbage cruncher is chewing away, and Columbo is yelling to Clayton. Clayton reaches up to his ear and yanks down, as if ripping out his hearing aid. Moments later, he does the same thing.
When Clayton is preparing to sneak up to Dudek's room, he meets Columbo at the elevator. He is wearing his hearing aid. As he comes out of the elevator, the hearing aid is out. He hides close to Dudek's room and then walks in... wearing the hearing aid again.
When Columbo first visits Nora at her "cottage," she tells him that it had been built for her when she was a child actress. Later, when Columbo is speaking with Mr. Fallen, Fallen tells him that Al Cumberland had given the house to Nora before they were married.