Revealing mistake: Jack Albertson's character is taking pictures of The Cartwrights and ranch hands. The video camera moves across the front of the prop camera as Albertson pushes and holds the button to take a picture. The shutter on the camera never opens and isn't open until he releases the button. In those days the shutter had to stay open an elongated time to enable the light to infiltrate the negative. People had to stay still during this time.
Man's Best Friend Is Not His Dog - S4-E6
Revealing mistake: As Schultz holds Newkirk's hat during the search, you can see "Dawson" written on the inside band. This was to insure that Richard Dawson (Newkirk) always had the right wardrobe pieces.
Crossroads - S1-E5
Revealing mistake: When Easy is paddling across the river to aid the British soldiers, there is a shot where the person closest to the camera (Bull Randleman) appears to be rowing, but there is nothing in his hands.
Revealing mistake: In the scene where the king and his entourage are walking through the crowd, someone in the crowd (right side) is wearing a watch on his left hand while applauding.
Rally 'Round the Flagg, Boys - S7-E21
Revealing mistake: When Col. Flagg holds his pistol up to stop Mr. Pak Sr. from leaving, you can see there is no magazine in the pistol.
Revealing mistake: When Bumblebee is knocked onto his side, Ratchet kneels down to shove him back onto his wheels. The only problem is that when Bumblebee drives away, the animators forgot to add Ratchet's leg (that was previously obscured) into the frame.
Come In, Your Time Is Up - S8-E4
Revealing mistake: In the very first scene Captain Mainwaring and Sergeant Wilson cast multiple shadows despite supposedly being in bright sunshine.
Revealing mistake: Part 3: When the U.S. squadron leader's plane crashes alongside the Akagi, the use of stock footage places an American fighter plane on the deck of what's supposed to be a Japanese ship. The star on its wing is visible as the flaming plane sweeps by in the background. (00:49:45)
Revealing mistake: Kevin McKidd's Scottish accent appears every now and then. For example in this episode, when he says that Marc Antony "negotiates with a whore and a dwarf at his side".
How to Succeed in Farming Without Really Trying - S3-E6
Revealing mistake: When the patroon is policing the area, raking and sweeping, they are not really raking or sweeping. They are just going through the motions but the rake and brooms are not touching the ground. (00:06:00 - 00:07:00)
Revealing mistake: When the coward is being branded using a red hot poker, you can see that the metal 'C' hasn't been heated at all when it is brought next to his face. Compare it to when they tested it on a piece of wood beforehand. The poker is also covered in a really fake-looking red paint. (02:02:55)
Revealing mistake: It's obvious by his hand movements that Gunner Graham isn't actually playing the piano.
Suggested correction: If I take some random episodes, S7E5 (01:54) or S3E1 (21:51) or S7E1 (13:21), it's either real or at the very least the touch matches the notes in time. This is all on YouTube for easy check-up. S8E2, which centers on him playing something complicated, doesn't show his hands, so avoids a mistake. Glimpses during opening credits are less well-matched over the seasons, but then, that is supposed to be the score only. Claims that it's all very obviously fake just don't seem to ring true.
Suggested correction: I have recently watched the whole run of the series, every single episode, and I do not agree for two reasons. First, there are no close-up shots of hands on the keyboard. Sometimes it's bound to be a recording, for example when the monsoon breaks and the piano is full of water. But that is not a mistake. Second, the show released its own LP record, and actor John Clegg is credited for playing one musical number on that album. So I'm not so sure if he wasn't the real pianist all along. It makes sense that they'd cast someone who could actually play well enough.
If you look carefully, it obvious to any one who plays the keyboard, he's not playing. Also its as plain as the nose on his face that in shots with him playing the accordion, it's a fake.
Of course the accordion is fake - that is just the one episode where they were sent to the front line, so they needed to do something. But I'd very much like to get an episode & time where it's "plain as the nose on his face" please, apart from special situations like in the pouring rain. (I repeat, no-one else is ever credited for the piano, not even on the record album; and it would be strange casting then, since he was always the mediocre pianist from day 1).
Hard Boiled - S2-E2
Revealing mistake: The blood pack is obvious as Benedict Arnold is shot in the thigh.
Revealing mistake: Supposedly in Liberia, the team takeoff in a helicopter. However, when they take off, the camera reveals the airfield, where several general aviation aircraft are parked. This is highly unlikely to be in Liberia, also the night lights seem to be somewhere in Cali (perhaps LA)). (00:27:20)
Revealing mistake: When Ms. Haman is shot by the soldiers, the moment that the gunshot that hits her is heard, and she is shot, there is already a massive, thick blood stain on her dress from where she is bleeding from. No gunshot wound on the planet can create an amount of blood that massive or thick in an instant. The blood stain was likely applied to her dress before filming the shot. (01:17:52)
Revealing mistake: When Malot lunges against the cage holding Savage, the "iron" bars bend inward. (00:30:25)
Revealing mistake: Near the end of the battle at the end of the episode, we see some Japanese troops coming out from the jungle. The Marines then shoot a machine gun, killing them. But pay attention to the ammo belt. All the bullets are blanks. (00:38:50)