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.