Stupidity: The villain of the episode is supposed to be a fearsome martial artist who killed with his bare hands dozens of people (a dozen alone is made of Mai Ling's relatives). This killing machine has one small weak point; he 'blinks' before striking. But it's not even a 'blink'; he squints. Hard. For long. Not even the worst amateur boxer has such a gigantic weak point. He also gets distracted by a helicopter flying in the distance forgetting completely about his opponent and letting them grab a gun and calmly point it at him.
Stupidity: Higgins tells Magnum that he needs to get out before he opens the safe. Magnum then gets all sassy and asks "Shall I open it?" and proceeds to activate the statuette that unveils it, then pauses. Higgins is outraged and then goes ahead and opens it dialing the combination. Higgins' behaviour here is absurd; he gave up and handed Magnum the victory in their petty squabble when Magnum proven nothing. Magnum is the security consultant of the house, it is unthinkable that he would not at least know where the safe is, but it's also rather obvious that he did not know the combination. You don't get a safe assuming that nobody will ever know where it is; keeping it out of sight and reach is a plus, but it's not really its point. (00:19:30)
Stupidity: You'd expect Magnum's friend Dan Cook to be quite smart and adept with military affairs and regulations, being an NCIS guy, but just look at the guys who tricks him; they both have terrible hair and sloppy care of the uniform, and the guy who greets him has a messy 'stache no Marine could wear. (00:09:30)
Stupidity: The gag with Magnum not noticing Higgins lurking at his home is fun, but for that to work he needs to completely overlook the fact that the lights are on, and walk perfectly backwards without jumping in surprise when he bumps the back of the leg against the dogs. (00:37:30)
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)
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)