The Case of the Red-Faced Thespian - S4-E12
Character mistake: Magnum quotes in his mind (right after the $20,000 turns up in Higgins' room) and then out loud (during the denouement) that "Old wounds heal slowly." The quote is from a movie he watched earlier...but it said "DEEP wounds heal better slowly." (00:30:55 - 00:35:40)
Character mistake: The coach of the Jororo team makes a joke about being cut by the king "Like Robespierre did to Louis XV in '89." That would have been Louis XVI (and not in "89" but (17) 93, although the year of the French Revolution is correct). (00:25:10)
Character mistake: Higgins remembers having met the sisters "37 years ago this July", and shows a "theatre program from Blackpool the summer I completed my upper second at Sandhurst." Considering the episode is set in 1983, Higgins would have still been in military academy in WW2, which contradicts the plethora of experiences in North Africa and Burma. It's more likely that John Hillerman misspoke and it was meant to be "47 years ago", before the war. (00:37:30)
Character mistake: Magnum is holding a stinky pickled egg while he bickers with his friends in Rick's car. TC calls the store chain Magnum has been hired to protect "Day-N-Night" instead of "Day-N-Dark." (00:22:00)
Character mistake: Magnum mutters that they can still make it to the second half of Bambi, "Thumper is probably still alive." Thumper does not die in "Bambi", as Magnum should know since he's seen the movie already. Props to him for being cautious with spoilers casually leaking a fake one, then?
Character mistake: Waldo's database entry from the CIA archive is quite odd. The most striking part is the "Basketball scholarship, 1983." Despite the way Rick reads it and reacts to it, the only way it could make sense if it referred to Waldo's son, or he'd have gotten it at the ripe age of 42 and 20 years after graduating from Yale. But it makes no sense that it would be there on his file, and contrasts with the succinct file on Skuler. (00:25:00)
Character mistake: Rick says "It's working, here it comes" a second too early, when the kid hasn't finished typing the name and hasn't launched the search just yet. (00:24:40)
Luther Gillis: File #521 - S4-E2
Character mistake: In the opening shot of the "Busy B", the name of the show on the marquee is "To young to care" (00:30:40)
Luther Gillis: File #521 - S4-E2
Character mistake: Agatha says that Higgins is teaching them "kung fu" although they all wear a karate gi and belts. Higgins then asks Luther to be a stand-in for the "jumping kick" demonstration, but the old lady charges at him with her hand at the ready for a karate chop. (00:16:00)
Operation: Silent Night - S4-E10
Character mistake: Higgins hearing the drunk sailor sing "Ukulele Lady" pitches in saying "Written in 1925 by Gus Kahn, Richard Whiting and Irving Berlin." The song was written by Kahn and Whiting only, who published it through Irving Berlin's eponymous record label. (00:10:50)
Squeeze Play - S4-E7
Character mistake: Misunderstanding which "Washington Senators" Mickey Dalrumple was referring to, Robin Masters says they went "out of existence in 1969." The Washington Senators ceased to exist with the 1971 season, before they relocated to become the Texas Rangers. (00:04:00)