Francine York said years later that she hated guest starring on this episode. She said Jack Klugman was fine, but Tony Randell was a "bastard," very nasty to her, and very snobbish. She suspected he was intimidated by her because he liked her so he was using "that old intimidation thing." He would sing opera and put her down if she didn't know the title of the song.
Felix's secret gravy recipe is a cup of beer and a teaspoon of dry mustard.