The funeral home featured in the stock shot is not in California. It is the luxurious Ephrussi de Rothschild villa and gardens in Saint-Jean-Cap-Ferrat on the French Riviera. This location is notably featured in the James Bond film Never Say Never Again (1983).
When Columbo is being paged over his car's police radio, for the first and only time, his call number is revealed; it is "194".
Near the end, there's an exterior shot with the 300 East 5th Street "Hard Rock Café" in the background. There is no connection to the worldwide chain founded in London in 1971, but it is featured on the back cover of The Doors' "Morrison Hotel" album and was the shooting location for Michael Jackson's "Beat It" video.
This episode was directed by actor Ben Gazzara.
This is the first time that you don't see the original murder take place.