Stupidity: The whole episode has heavy farce tones and shouldn't be taken seriously, because the main plot point does not make sense; unless somehow he was able to produce remains of a body in the plane wreckage, Mr. MacLeish would have never been legally declared dead.
Foiled Again - S3-E7
Stupidity: Magnum hears from Carol that she's "sorry" and turning to the left he witnesses Higgins getting dragged in court. The two policemen who are escorting him stop at distance from the building, no obstacle or pressure, no reason other than providing a dramatic shot. (00:23:50)
Stupidity: Magnum saves Higgins from a scheme that was amazingly poorly planned to begin with; forgetting for a moment that as estate manager, Higgins should be very well aware of the closing time of 'the bank' (as if there were just one in Hawaii) even more than Magnum, Catherine could have not just relied on Higgins being this ignorant.
Stupidity: Not Darcey nor anyone on the team including the good natured coach and people who care for him finds strange in the least that the doctor keeps giving him cortisone shots for a year. Anyone who played professionally or had to deal with injuries in any way (which should include Magnum too with the beatings he took) would find amazingly strange such a treatment this prolonged and with no benefit.
Stupidity: Kate is supposed to nail the biggest scoop of her career on Bannister and bets all of her career on it, really. but she apparently never bothered to check out how the guy looks or sounds, since all it takes is hearing one sentence from him thanks to the tape from TV, to recognize who he is.
Stupidity: Magnum is well aware that the person who randomly dropped from the tree to get his attention (!) is all a ruse, but he just leaves Kendall alone to go check him out, thinking to himself through interior monologue that "walking into the trap may keep Kendall out of it." The guy is playing possum face down on the lawn, far off in the distance. How would THAT guy be a more immediate threat to the woman you are bodyguarding, than just telling her "go ahead on your own through the trees"? Who reasons like that, with obviously more people lurking, since the first is merely a diversion? How do the bad guys even think that this could work? And yet, it does. (00:23:20)
The Taking of Dick McWilliams - S2-E9
Stupidity: If the big Hawaiian dude who is a drinking and fishing buddy of your husband is showing up with a stocking on his face and pretends to kidnap him using the car he always uses, chances are you are gonna recognize him instantly - but not if you are in a TV episode.
Stupidity: Higgins believes TC's story about leaning on the gate and causing sparks, but it's barely 20 seconds between the moment the lights go off and when he shows up; in 20 seconds he couldn't be from the gate of the five acres estate to the mansion's door if he ran to it, surely not in a casual night saunter. (00:39:00)
Stupidity: The good fellas at Laseronics have a CCTV camera Joy and Magnum get past, which somehow detects her sneezing from the other end of a huge hall with active machinery. The camera does not detect the sound in Higgins' cell, and they don't give a damn about the fact that the camera has not been broadcasting anything since someone threw a towel on it. Strangest security system ever. (00:37:15)
Stupidity: The whole knife fight scene is pure silliness; the two got married - when and how, would be nice to know, since it was the middle of the night - and already planned to escape. They are on the car, and just the cranky maitresse talking to them from the stairs; they could and should simply drive off, and nobody could have done anything to stop them. Instead he just stays there to reply to her and gets back in the alley to have a pointless knife fight with the pimp.
Stupidity: The poor soldier Magnum is looking for during the whole episode falls into the water once the agent shoots at him. You can't really tell if he was hit, where, how badly, but does not matter; somehow, in a reverse of the proverbial plot armor, Magnum and his girlfriend just assume he's dead and don't even attempt to dive in to save him. He's dead, because they read the script and know he is. (00:45:00)
Thank Heaven for Little Girls and Big Ones Too - S1-E4
Stupidity: It is stated that the security has been "really tightened" because of the Gauguin, and "the place is harder to break in than a safe." So, what's the security for this multimillionaire picture? An alarm that goes off if someone touches the painting, but it switched off completely if just someone flips an unprotected switch positioned less than 10 feet away. Even a kid could dispose of that - which is what happens - but it's not like a siren going off in the middle of a remote estate would discourage a thief that can simply run away with it. (00:23:25)