Deliberate mistake: The show is set in New York. Joey was a cast member on Days of Our Lives, which is filmed in Los Angeles, but is still always around.
Twenty-something girls vs. thirty-something women - S2-E17
Deliberate mistake: In the scene at the beach party, when Carrie brings everyone beers, Miranda says "There's so much foam, I could ski on the head," but the cups are tipped toward camera and you can see there's no foam at all.
Deliberate mistake: Lindsay is not at Caleb's funeral in the last episode of season 2, "The Dearly Beloved". It's unlikely that she would have missed it - she is still on good terms with him and he is her father, the only reason she left was to be with her mother, not because she didn't love Caleb.Obviously they didn't want to create another drama with having Lindsay there while they had to focus on the important story-lines - Caleb's death, Kirsten's drinking and Marissa shooting Trey.
Deliberate mistake: About halfway through the show, Roz and Daphne are in the kitchen talking. Daphne pours water into the teapot - but there is no steam coming from the kettle, nor any sound of a boiling/just boiled kettle. No self-respecting Brit would make tea with water that wasn't boiling.
Deliberate mistake: When Mary gets to the school where she is going to be teaching, all the children are standing outside wearing shoes. However when they come in to the school they are barefoot. I have a feeling this was done to show how poor the community she was teaching in was supposed to be, but it looked like too cold and rainy of a day to let the actors be outside barefoot.
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: 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: In Episode 7, "Bad Moon Rising": When Cash meets Sasha at The Haven, she mentions "Eddie and his bodyguards being blown away". But Eddie was not "blown away", he was neatly decapitated, and in addition, none of his bodyguards were killed. Julian specifically said that he would let them live to elect a new leader. Sasha was present, and would know this.
Deliberate mistake: The layout of the Walsh house, both interior and exterior, is different in the pilot than it is in the rest of the series.
Deliberate mistake: Around the 26 minute mark, when Charles Brandon joins Margaret for a game of cards during their voyage to Portugal, Margaret has a glass of wine (and later Brandon) in which the liquid is not sloshing around As It Should Be on a ship that is rocking and swaying the way it should. (00:26:10)
Deliberate mistake: Unavoidable, but still noteworthy: At the beginning of season 2, all the story lines pick up where they left of from at the end of season one; indicating that not much time has elapsed. In spite of this, most of the cast have different haircuts, Dana has grown out her fringe, and Tina suddenly has a baby bump.
Deliberate mistake: In the episode January 2011 where Stephanie puts a slide in the living room, when Stephanie goes down it, you can see she is using a stunt double because her hair is thicker and they cover her face with her arm.
Deliberate mistake: Probably best for filming the scene, but Jennifer Hart pulls up and parks her car on the street on a red curb in front of an ambulance and walks away. (00:10:12)
Deliberate mistake: The judge grants wheelchair bound Hilda Mars a million dollar settlement for her injuries. Then Sydney confronts her outside and wrestles her up out of the chair in which Hilda fakes a tumble down the steps. That night Hilda's attorney visits Sydney and admits he knows Hilda is a con who got away it instead of calling it out to the judge.
Deliberate mistake: In the opening of seasons 2 onwards, there is a photo of Olivia outside the Church with the family. This is a scene from Season 1 Easter Story. However, it had to be from an outtake because the position of Erin, the absence of Jason, is different than what is shown in the episode. It's just something I noticed when I identified from where the shot was taken.