Audio problem: Magnum poses as an envoy from Icepick. When he takes his feet off the desk, he says an "Okay" that the microphone struggles to pick up. (00:41:05)
Revealing mistake: When the brawl in Charlie's office begins, Tom Selleck changes into his stuntman who can be seen as he quickly stands and punches a goon. (00:41:50)
Continuity mistake: When the champion sends TC flying with some sort of flamboyant knee to the face, before TC gets to the ground you can see the towel on the top rope being quite distant from the turnbuckle. In the rest of the scene it is right by it. (00:42:45)
Continuity mistake: When TC hulks up from the stool for his last round, Rick has his right hand on the towel, which becomes the left hand as TC parries yet another haymaker. (00:43:40)
Revealing mistake: All the 'boxing' in the episode is unrealistic pure 80s Hollywood hot camp garbage, but the finishing blow of the final match in particular is miles off, bad even for the low standards of that sort of 'action'. (00:44:10)
Continuity mistake: When Higgins calls "Buster" and "Bobby K", a strong shadow appears on his forehead in the wider angles, nothing of the sort in close-ups. (00:47:35)
Continuity mistake: Throughout the episode, which covers a timespan of a couple of weeks, the various patrons of the bar/club where the fights take place for the most part are around for every match, which is not out of the ordinary but...wearing the same clothes too, that's more unusual.
Continuity mistake: Magnum is about to leave after the slightly awkward introduction to Holly Fox, but she calls him back saying "Maybe there *is* something you could help me with." He sticks his head back into the room, and you can see the glasses' left arm is above the shirt collar. Next shot and it went underneath. (00:13:40)
Continuity mistake: The chopper takes off from Higgie's un-birthday party, looking as usual. It flies over a shore to thwart Holly's plan, and doing so it has the flotation skids from a different chopper's stock footage. It is therefore also missing the birthday banner, that is present again in the finale. (00:45:10)
Audio problem: In their struggle on the lookout point, Don Cassidy throws the gun over the railing. A clattering noise is heard as if the gun fell on a solid pavement, but the way the action is shown, it went down in a spot where a few seconds later during the suicide attempt there's nothing but a freefall. (00:46:05)
Revealing mistake: The closing shot of the episode shows the lookout point platform where the suicide attempt happened...but also, below it, you can catch a glimpse of an additional platform, and a rope probably used for safety reasons as well. Needless to say, it was not featured in the dramatic shot of Holly looking down into the abyss. (00:46:55 - 00:47:40)
Audio problem: The whole episode revolves around a radio DJ, who calls the various songs - however, for licensing issues, contrary to what the DJ advertises, the songs (including at least four Beatles hits, Elton John, and a version of Satisfaction that already appeared in the celebrated Season 3 opener) are not the originals, but stock covers.
Operation: Silent Night - S4-E10
Continuity mistake: In the opening shots, the helicopter is the N58243 one with flotation pads, but as soon as it starts malfunctioning, the pads thin up and we switch to the usual chopper. The skids change shape back and forth again once. (00:02:05)
Operation: Silent Night - S4-E10
Visible crew/equipment: When TC makes a successful crash landing on Frenchman's Island everyone exits the chopper, and as Rick says, "Hey, you know what this place is," the boom microphone is visible moving around at the bottom left of the screen. (00:05:30)
