During the first scene when Byrne Piven is on the phone talking to (Mac). He is squeezing an apple in his hand. The camera cuts to a shot of one of the henchmen and back to Piven who is now squeezing an orange.
In the latter half of the show when Mac shows up at the shack that Magnum and Maria spent the night in; Mac is sporting a different mustache than was seen earlier at TC's office.
Higgins says the dogs are away, being groomed. Other than having their claws trimmed, dobermans, which are short-hairs, do not need grooming. A bath is all it takes.
Byrne Piven's first name is misspelled as "Bryne" during the opening credits.
Magnum tries to build a "bunker" from am ordinary couch and chair. These provide no protection whatsoever from gunfire.