As Magnum and TC take off in the chopper to search for Holly, the birthday sign for Higgins is attached, but is absent in the next scene of the chopper speeding over the coastline. It is back again in the next scene as the chopper rises above the lookout.
There were, in fact two different Hughes/MD 500D-369 helicopters. The one carrying the Higgins birthday greeting was N1095A. The one flying over the ocean was N58428.
The radio station Holly was broadcasting from was KTDE (K-Tide) but at the end the recorded program gave the call sign announcement as K-REST.
When Holley Hudson hugs Don Cassidy her fingernails are short. Later, on Kaheo Point, when Holley points and cocks the revolver at Cassidy, the hand holding the gun has long fingernails.
At the end of show, the camera shot is from a helicopter, as it shows the platform Holly was going to jump from. The safety platform built below the actual platform and the safety harness used to prevent Holly from falling is visible.
When the helicopter flies up to the cliff facing Holly the pilot is not TC but the true helicopter pilot wearing a black face covering. He is seen twice as it changes between exterior and interior shots.
Magnum is shown saluting enlisted men in the early flashback scene while arriving in the Jeep. This is obviously meant to be in the jungles of Vietnam, which would be a combat zone. Except while indoors, salutes are not given in a combat zone as it identifies superior officers to enemy snipers who may be watching the area.
In the opening scene, Magnum, in combat fatigues and driving in the Jeep, salutes a number of soldiers as he drives into the combat base area in the flashback. Magnum initiates the salute, which the soldiers return. However, Magnum is an officer and the other soldiers are enlisted men. An officer does not initiate a salute. The enlisted man would and would hold the salute until the officer has completed his.
Maggie Poole is a Lieutenant, not a Lieutenant Commander.
Magnum refers to Tidewater as a small town in Virginia. However, the Tidewater region includes the land east of the Fall Line, the natural border with the Piedmont Region. It includes Hampton Roads, the rest of the Virginia Peninsula, the Middle Peninsula, the Northern Neck, and the Eastern Shore.