Revealing mistake: During the fight scene at the end when Buffy is fighting the demons you see her throw one of the demons off the platform. If you watch him fall you can see him land safely on a conveniently placed mat. (00:38:10)
Revealing mistake: When Georgia walks into Billy's office naked, a triangle-lamp will cover her "naked" breasts. Look closely, for at one point you can see the white, strapless bra.
Revealing mistake: Dead lady blinks when Barnaby enters the room.
Revealing mistake: A little oversight on the part of the producers. At the final scores that we are shown, Amy has $10,000, TJ has $9,800, and Travis has $2,400. This all adds up to $22,200. Even if they only answered $400 questions (which we can see that they don't), that's about 55 questions at best, only in the first half. That would run way longer, probably about three or four times as long, as any normal game show. And there's no mention of any other rules regarding the scores so there's no reason to think that there are bonus questions that could raise it that much.
Revealing mistake: Creek reads a newspaper article about Tracy, a missing schoolgirl. The first paragraph of the article is about the schoolgirl, but the rest is about John Major (who had just been ousted by Tony Blair as prime minister when the episode was first aired, but, assuming this was filmed some months earlier, would still have been in power). The first line of the article following the first paragraph starts mid-sentence, as if the first paragraph has simply been pasted over the top of the existing article. This mistake is surprising as there is a photograph of John Major alongside the article and the newspaper remains in shot long enough for it to be spotted without the need to pause the DVD or video.
Demon Suite Murder Case: File 2 - S1-E17
Revealing mistake: When Kindaichi looks the name up in the French dictionary, the pages are entirely made up of the same paragraph repeated over and over. (00:08:50)