There are two kinds of owl seen in Hawaii---the native pueo, and the introduced barn owl. The owl seen in this episode was neither.
In this episode, the Ferrari is shown with the top up. This occurs very rarely.
In a scene in Higgins' office with Magnum and Laura, Higgins mentions that he and Robin raced the "Lucky Lady" in the 1976 TransPac (Transpacific Yacht Race). John Hillerman played a hit man named McTeague in the movie Lucky Lady (1975) starring Liza Minnelli, Gene Hackman and Burt Reynolds. The boat the characters used in their rum running exploits in the movie was named the "Lucky Lady."
Jillie Mack, the uncredited tap dancer auditioning for the telethon, is Tom Selleck's second and current wife. She appeared in two other episodes as well: "Rembrandt's Girl" (Rembrandt's Girl (1984)) and a guest starring role in "Professor Jonathan Higgins" (Professor Jonathan Higgins (1985)) as a British punk rocker.
This is the first of three Magnum, P.I. (1980) episodes which David Hemmings directed--Fragments (1984), Compulsion (1985) and Let Me Hear the Music (1985). He also was a cast member in the middle of listed episodes.