The skids on TC's helicopter change while searching for Dick among the islands.
The registration number on TC's MD500 changes from N1095A to N58243 during the search for the kidnapper's hideout. The skids are thicker on N58243.
The car used for the kidnapping is a 1966 Ford Galaxie 2 door painted bright blue. Its license plate number ends in 17. A blue 1966 Galaxie is visible in the group of cars heading into the tunnel when TC and TM are following in the helicopter. Later, when TM talks to Gloria he asks her if she own a "1974 blue sedan, license number AFF 444". Parked in front of Gloria's apartment is a 1974 sedan but it's a dark Mercury Marquis with a license number ending 718.
When the orange Jeepster Commando stops to pick up the ransom money, Rick says it has no license plates. No license plates are visible before the Jeepster enters the tunnel. When TC flies chopper to look into the exit of the tunnel, the Jeepster is visible and now has a front license plate.
Rick refers to the kidnapper's ransom pickup vehicle as a "Bronco" which is a Ford, but it is a Jeep.
Obvious stunt double for Magnum during his fight with Nishimoto.
After landing and walking up to the shack on stilts in the "koolau" islands, a man can be seen, on the back-end of the shack through the raised area, walking and dragging a cable of some kind.
All of the actors mispronounce the common Japanese given name of the character "Mitsue" as "Mitt-soo" instead of correctly as "Mee-tsu-eh"