When Digger jumps from the truck after she and Higgins find T.C. treed by Zeus and Apollo, she is brandishing a hand gun in her right hand. When she arrives at the tree she no longer has the hand gun and both hands are on her hips.
As Magnum and Digger climb up the mountain after rescuing Higgins, in the longer shots "Higgins" is only a dummy. Digger also appears to be a stunt person wearing a long black wig.
As Higgins pulls the Audi to the side of the road, after Lisa (Tom Selleck's then wife) drops her moped into a ditch, crew and equipment can be seen to the right through the car's windshield.
Digger (Erin) Gray said she had an M16 in her vehicle. Rick was carrying an Ingram Mac-10 (most likely full auto) patrolling the gate of Robin's Nest. Full auto machine guns have been outlawed in Hawaii since its Statehood except for active duty military and law enforcement.