Plot hole: Magnum asks Mac to "put together a list of ships that went down in that channel in the last 200 years." He gets the list, and it turns out of the ship of interest, amongst the many, is the Eldora, "a Spanish galleon used to carry the plunder back from Spain's numerous conquests." That sounds like something quite more ancient than 200 years, however it can be said that galleons were still in use in the early XVIII century. However, when Professor Martinez hears the news, she says that it supports her theory of early contacts between native Hawaiians and Conquistadores, which would put it centuries off range again. It also begs the question; why would the US Navy intelligence know of that galleon (but without any location or additional info) but the scholar at the university who is studying and publishing a book on that very subject is totally oblivious about it? Even Higgins heard about it.
Magnum, P.I. (1980)
1 plot hole in Dead Man's Channel - chronological order
Starring: Tom Selleck, Roger E. Mosley, John Hillerman, Larry Manetti
Other mistake: With power out Magnum somehow lights the gas stove with the knob, which is electric. Should have used a match. (00:26:40)
More quotes from Magnum, P.I.
Trivia: At the awards ceremony, three men seated at a table together resemble three detectives from 1970s TV shows. Detective Mike Stone (played by Karl Malden) from ABC's Streets of San Francisco; Detective Frank Columbo (played by Peter Falk) from NBC's Columbo; and Detective Theo Kojak (played by Telly Savalas) from CBS's Kojak. (00:07:20)