Series creator Tracy Torme left the show after this episode finished production.
Both the name of the episode and the name for Doyle's assistant comes from mystery writer Agatha Christie. Murder Most Foul is the name of a novel featuring Christie's popular Miss Marple.
The Reginald Doyle character based on Sherlock Holmes got his last name from Holmes' creator, Arthur Conan Doyle.
The professor plays a character called "Reginald Doyle"; in real life, Reginald Aubrey Doyle was an infamous person in Australia in the 1950's who was jailed for contempt of court and then jailed for 10 years for forgery, fraud and theft.
Both Brian McNamara, who played Dr. Dunhill, and Brigid Brannagh, who played Erin, starred together in 'Army Wives (2007)'