John Hillerman would later play the role of Dr. Watson in the TV movie "Hands of a Murderer" (1990).
The title is a variation on the proverb: Home is where the heart (or hearth) is.
This episode establishes that the character of Agatha Chumley existed as a friend of Higgins on Oahu back in 1976, yet she does not appear on Magnum P.I. as a this character until Black on White (1982) in 1982, the show's third season, all the while as the actress who plays Agatha, Gillian Dobb, played other characters before that.