This episode was the first to air on Sundays, as a one-time special to see if the series would draw enough ratings to be renewed for the rest of season (the show it replaced; The Family Holvak (1975), had finished production and ran off a few more episodes in December). NBC, facing a devastating drop in its overall ratings, wanted to keep Ellery Queen (1975) as "quality" programming if there was any way it could.
This episode was designed to bring a galaxy of radio performers of the 1940s and 1950s to the screen, playing approximations of their characters from past shows.
Eve Arden's radio character is a school principal. She also played a school principal in the movie, Grease (1978).
Betty White and Nan Martin would have another mutual brush with death in It's a Miserable Life (1986); White's character would unleash an uncharacteristic tirade of invective that would cause Martin's character to have a heart attack.