Yug Ylimaf - S11-E4
Deliberate mistake: The time machine reverting causes everything in life to go backwards. However, although the characters' actions are reversed, their dialogue is always spoken forwards and not backwards. (00:08:00)
Thorpe Park - S1-E3
Deliberate mistake: In the scene where Jay spots the "car full o' muff" and they follow the car until it turns left (just after Jay says he'd "give a left bollock for em"), when it pulls away, the shot is flipped. The number plate is reversed, all of the logos on the back of the car are backwards, and the car is actually turning right, as it heads to the right hand side of the road. The shot is just flipped to make it look like they're turning left. (00:10:50)
Wrestling with Demons - S3-E12
Deliberate mistake: When Piper froze the demons (near the wrestling) one of the demons moved when she froze him.
Deliberate mistake: Many times throughout the show, a large bandage or makeup blot is visible on Lea Michele's right wrist, which is used to cover up her "I Believe" tattoo. This is most visible during "Don't Rain On My Parade" and her "Poker Face" and "For Good" duets.
How to Win Friends and Influence Nazis - S3-E7
Deliberate mistake: Burkhalter pulls some papers out of his bags marked "Top Secret." Why would German papers be marked in English, so the prisoners know what not to look at?
Deliberate mistake: In the scene where the ministers are all crammed into the train carriage if you look over Jim's shoulder there is a sign ("Notice" "In case of Fire" etc), while the headers are in English the actually paragraphs are written in gibberish.
Pipe Dreams - S3-E11
Deliberate mistake: When Zack brings an oil covered Becky to the biology teacher, you can see that it's a fake duck.
Deliberate mistake: Very often, during Skype or other video chat conversations, the people on the computer screen look left or right when talking to someone who is not directly in front of the screen. Although it certainly helps the viewers understand who's talking to whom (which is why I assume it's a 'deliberate mistake'), it isn't realistic, since it implies that the people on the screen are actually constantly looking away from their computer instead of at their screen or webcam.
Deliberate mistake: Whenever a punch is thrown in this series, the punch either stops before it hits the person or goes beside them. It's most obvious in the last episode when General Melchett says 'Excellent native cockney wit' and punches Baldrick.
Deliberate mistake: The first 10 episodes of Season 5 were shot in a totally different order than they were aired. As a result, Jamie's size during her pregnancy is very inconsistent at the beginning of the season. In particular, she gets much smaller between episode 8 and episode 9 because episode 9 was originally supposed to air earlier in the season.
Deliberate mistake: Rob is about to leave his room, and he opens the bedroom door to the noise of a loud music box that was originally being made by Laura's music box that holds jewellery in it.
Deliberate mistake: Spongebob blew a bubble to capture the butterfly while wearing that fishbowl on his head.
Land of Hold/Penny Henny - S2-E17
Deliberate mistake: When Garfield brings Jon to the broken TV, the scene's animation is still unrendered. (00:01:04)
Deliberate mistake: When Tim Taylor is telling Mike about his show "Tool Time," he mentions that it lasted for 8 years. Later in the episode when Mike is asking Tim why he stopped doing the show, Tim says it's because he found it challenging to keep the show great and not run out of ideas. Firstly, while Home Improvement ran for 8 years, the show within the show of "Tool Time" was already a couple years old when Home Improvement started, as evidenced by the fact that its season 3 episode "Fifth Anniversary" was about "Tool Time" celebrating its 5th anniversary, as the title suggests. Additionally, Tim didn't quit "Tool Time" for the reasons he stated here. He spontaneously quit over creative differences with Binford's new president, who was turning the show into a sensationalist Jerry Springer type of format, and because his wife Jill had just been given a job in Indiana, and he decided the family would move there to support her.
Deliberate mistake: At the very end, Tommy And Merton discover the video tape which contain pictures of Merton that had been film by her sister Beckie, but the movie was filmed and the time ''rewind'' because of the spell. So in reality, the movie was never filmed.
Jessica's First Christmas - S2-E7
Deliberate mistake: Just before father O'Hara explains to Frank why he isn't in the nativity play he says to Betty "Perhaps I will have that cup of tea after all Mrs. Spencer" Betty goes to the kitchen but father O'Hara never gets his cup of tea.
Suggested correction: Perhaps Betty just forgot.
Deliberate mistake: At the beginning of the episode, when Doug and Carrie are in the shower, you see their silhouettes. The first mistake is that for the silhouettes to show like that they have to be evenly backlit which wouldn't make sense in the shower. The second mistake is a little more subtle; you can see the outline where the actor's bathing suits are (inevitably) slightly larger than the bodies. There is also a slight darkening in the areas where the bathing suits cover skin. (both of these things are much easier to see on Carrie than Doug because of her smoother figure and skin tone).
Deliberate mistake: Season 2, episode 10: After Matt is supposed to be dead underwater, you can see air bubbles coming out from his nose in a close-up, and in a far away shot his head is above the water so the actor can breathe.