Revealing mistake: In the classic ending of the episode, there's an obvious use of a dummy who falls in unnatural, stiff motion. (00:45:35)
Continuity mistake: Magnum and TC are looking closely at Magnum's client punching the lights out of his sparring partner. After a brief cut to the boxer finishing the guy off, TC suddenly has a baseball hat on. (00:33:40)
Continuity mistake: After the introductory scene in Ulster, Father Paddy McGuinness flies to Hawaii. The United airlines plane shown approaching the islands though is two different planes; the colors are different. In flight it has a horizontal gradient red and blue stripe, the second plane, shot during its landing, has a blue horizontal stripe with a red wave-like strip underneath. (00:06:45)
Continuity mistake: During the farewell to Brigadier Faulkes and Father McGuinness, the people in the background never transition from one shot to the reverse, effectively disappearing. (00:42:00)
Continuity mistake: The rosary in Father Paddy's hand changes position - look at the metal tag - before and after Higgins' exits his room. (00:32:00)
Continuity mistake: Right after the scene at the rooftop bar is a wrap, there's a shot of TC's helicopter that features a different serial number from the normal one, and padded skids. Next shot and the skids slimmed down. They go back to the padding for other shots after Magnum photographs the cetacea. (00:27:00)
Continuity mistake: When Higgins raises his glass for a doomed to fail toast to the Queen, the level of so called scotch in his plastic cup changes between shots. (00:25:35)
Continuity mistake: The bartender at the Beach Bar serves Higgins the authentic Hawaiian scotch. It looks bad enough in close-up, but when Higgins holds it in hand the colour is even paler and the straw has even messier and more disgusting hair on top of the hula dancer doll. (00:24:35)
Continuity mistake: Father Paddy spots Higgins staring at him at the 'Beach Bar' and exclaims the title of the episode. The glass of watered down drink next to him is full. Next shot and it's almost empty, change and it's full again, etc. (00:23:30)
Continuity mistake: Higgins approaches the concierge of the Low Surf Motel, manned by none other than Donald P. Bellisario, the producer. There's a drunk man leaning to the desk and clinging to his bottle of booze; in the first shot, to the very left of the frame you can spot his right hand moves away from the bottle's neck and goes on the counter. Change of angle, and the guy is back holding the bottle with both hands. (00:21:15)
Continuity mistake: Magnum walks out of the bar with 'Uncle Paddy'. As they take position and he takes the photo, extras are recycled - for instance the woman in long purple dress walks in the same direction in different shots. (00:11:00)
Continuity mistake: When Father Paddy McGuinness toasts saying "Erin go Bragh", the cigarette in his hand gained length compared to the butt he lit just a moment before. (00:09:00)
Continuity mistake: When Magnum is tailing Legs at the beginning of the episode, extras are recycled continuously walking left and right in the crowd. In particular, a guy with a pink shirt and light beige pants and suitcase is on both sides of the stream of Japanese tourists (behind Magnum when he stops the first time, and behind Legs when she smiles after Magnum takes a picture). (00:07:35)
Other mistake: The killer is finally in action; they get a semiautomatic with a silencer from a case, then they do an ominous gun-in-hand walk bit (filmic stereotype where someone just walks with a gun out for no reason instead of concealing it). The shadow of the gun there though shows no sign of a silencer. The killer shoots indeed with a silencer - the audio implies that - but in the shadow you can see it is now a revolver. (00:44:20)
Factual error: This episode is set during a party happening on the weekend of Spring equinox, which means end of March. but it's also happening during a devastating hurricane. No hurricane (not tropical storm) has ever occurred in Hawaii in that month or anytime close to that; hurricane season in the Pacific starts at its earliest in May, and used to begin towards July in the 1980s climate.
Continuity mistake: When Wanda Martine, Princess of Turbia has a giggling fit at the expense of Candice Wingate's dead husband, she holds no glass, but was holding one in the previous shot. (00:24:40)
Revealing mistake: The criminals have to get back inside the house because the cars for their getaway are "waist deep in mud", but they show no sign of having been anywhere near them; their shoes and bell bottom jeans are spotless. (00:22:35)
Continuity mistake: When Prince Roland calls the bandit "Impressive, but foolish", his wife's hand is on the table holding a cocktail umbrella all of a sudden at the cut. Later in the same scene her other hand holding a glass peeks in view showing she is drinking, but in an intermediate shot she is actually pouring the drink in another glass, moving the hand in another direction. (00:23:20)
Continuity mistake: The wine stain on Higgins' chest changes shape and size throughout the episode; in particular you can notice from the wine cellar to the sequence upstairs when Magnum spills the drink the stain gets longer and thicker on the button line. (00:18:30 - 00:19:10)
Visible crew/equipment: When Higgins whispers to the dogs to 'Stay' after the ruthless home invader shot a hole in the barrel, in the close-up of the dogs you can see in the background a crew member in the upper right corner, by the broken barrel. (00:18:00)