This story introduces a fourth character to be played by Jeff MacKay. He started as a fellow named "Ski", then came on board in a semi-regular basis as Magnum's old Navy buddy Lieutenant "Mac" McReynolds. After Mac's death, he appeared a number of times as con man Jim Bonnick, and then appeared in this episode as the Coroner.
Magnum's fantasy character smokes Lucky Strike cigarettes in a period-accurate green pack. After America's entry into WWII the green label (which can be seen in this episode) was changed, reportedly so that the copper used in the green ink could be used for the manufacturing of war materials.
In this episode the audience gets to hear John Hillerman's normal Texas-inflected speaking voice.
The vintage lighter on the desk is a pre-war Ronson Touch Tip. It uses a metal "match" that rests with its tip in the well of lighter fluid. The striker is next to the hole for the "match." A similar type of lighter is found on Phillip Marlowe's desk in The Maltese Falcon (1941).
Although his 1940s alter ego practically chain smokes, Tom Selleck does not actually smoke cigarettes. His father gave him a gold watch for not drinking, smoking, or swearing before his 21st birthday. (Ironically, when he first started in show business, Tom was a model in cigarette ads.)