Other mistake: Olivia Ross crushes in anger the paper cup she was drinking coffee from - and she does not wet her hand or stain her perfect white dress doing so. (00:23:25)
Continuity mistake: Searching the trailer, Magnum tells his friends the suicide theory. Rick in close-up is holding the flashlight in the same left hand he is leaning against the drawers with, but it is in his right hand at the cut. (00:38:50)
Visible crew/equipment: When Olivia thanks Magnum for his help Higgins walks over and tells her the hospital called, then right after Higgins says, "He appears to be improving," the tip of the moving boom mic dips into view over Higgins, at the top of the screen. (00:42:25)
Continuity mistake: By the deathbed of her husband, Olivia Ross asks, startled by Magnum "What are you doing here?" Her right arm position changes (along the railing or not) depending on the camera angle. (00:45:35)
Plot hole: With the murder happening literally on tape, it's quite extraordinary and inexplicable that the police did not acquire the footage as evidence, especially with film buff Lieutenant Tanaka investigating, who is not fooled by the culprit's act. The footage would have been used for insurance reasons as well, and instead it is reduced to some novelty everyone checks out just to fight boredom on an evening at the estate.
Continuity mistake: The director, Myrt Callahan, is talking to the producer while Higgins is on the phone with Robin Masters. Knox says that people can grieve and work at the same time, and she has both arms forward, but in the background when the camera focus is on Higgins we see her right hand on her waist.
Continuity mistake: Magnum drives the Ferrari to the National Memorial Cemetery of the Pacific with the sky being overcast. That's just the establishing shot though, because the sky is blue and the sun brightly shines in the rest of the scene. (00:07:45)
Continuity mistake: Magnum meets his new client. He asks "Have we met somewhere?", with his fingertips touching. "We were briefed together once, at Da Nang" the client replies, while Magnum lowers his hands and puts them on his hips. New shot, and he is again in the previous position, with the fingers touching. Similarly, the client mistakenly has his arms crossed a couple Transitions later when he says the two teams never hooked up. (00:08:30)
Visible crew/equipment: After Taylor gives Magnum the bottle of champagne Magnum heads to the couch, and when he sits down the white T-mark is visible on the floor, in front of Taylor. (00:15:10)
Continuity mistake: Taylor asks Magnum if anything happened to Linda. Magnum says "No!" twice; in the first shot his left arm is on top of the back of the couch, in the next one it's slumped into one of the pillows. (00:15:20)
Continuity mistake: Tailing Cam Chung with his Ferrari, Magnum does not have to go too far, seemingly, since he keeps meeting the same people over and over. A guy with a red T-shirt under a plaid shirt, a woman with a purple dress, one man with a blue tee and a single horizontal stripe, a man sporting a 'stache and wearing jeans and a pale blue Hawaiian shirt, etc. (00:21:00)
Continuity mistake: When Ed Kanfer's widow tells Taylor "But he's gone", her hands are not on his shoulders, where they appear in the next shot. (00:32:10)
Continuity mistake: There's obvious recycled footage to pad the episode during the approach of the chopper to the "fishing spot"; they take off with a chopper with normal skids and no doors, but the one flying over the ocean has flotation pads and its doors in place. The pilot is also wearing beige flare pants and not TC's jeans. The same mistake happens when he flies Magnum over, same recycled footage. (00:35:45)
Audio problem: The chopper is so noisy that people in it can barely talk to each other over the noise (as made clear abundant times in the series, including the previous episode when they "muted" Higgins switching off his intercom), but Thomas and TC are having a conversation while the helicopter is hovering meters above and Magnum is still with his feet in the parking lot. TC's lines are also neatly dubbed in. (00:39:00)
Other mistake: In less than 30 seconds of uninterrupted dialogue, the bomb advances from 1:05 to 11 seconds to go. (00:45:50 - 00:46:15)
Factual error: At the end of the episode, they bring flowers on the tomb at the Memorial cemetery, but given the crime committed, the vet would have been denied to be buried with those honors.
Plot hole: Taylor has the case scouted in such a way that you'd wonder what did he even need Magnum for in the first place; somehow he knows that the bad guy is in Hawaii (which is where the widow happens to live too), he knows he is seeing some girl and who she is, and got a picture of her too. If Magnum did what he asked, he would have arranged a meeting with her away from the gorillas - he does not insist to accompany him or anything of the sort, and in fact he needed only TC for that. Also, somehow Taylor knows as well where the bad guy's hideout is, but Magnum never returned with that information.
Plot hole: Taylor sets a timer on the claymore mine to make it explode within 10 minutes instead of by passage or by remote control, which is already pretty inefficient considering he went through the trouble of altering the original design, but even with that considered, it's inexplicable how Taylor knew that his target would be at that particular gazebo of the large estate, precisely at that time, within 10 minutes. To even get there he needed to ask TC, surely he's not privy to the victim's every habit nor schedule.
The Elmo Ziller Story - S2-E20
Factual error: At the beginning of the episode, the captions say; "Texas Hill Country." Later, Elmo explains the case and mentions to Magnum that it happened "outside El Paso." Very much outside, since El Paso is nowhere near Hill Country, hundreds off to the West. (00:01:35 - 00:15:40)
The Elmo Ziller Story - S2-E20
Continuity mistake: Magnum arrives to his place sporting a V-shaped patch of sweat down his shirt, but inside the guesthouse his clothes are already perfectly dry. (00:04:45)