Plot hole: When teenage Prue has run away with the demon, and Phoebe and Piper find her in the park, teenage Prue is 'killed'. Her sisters drive her home to get Leo to heal her, but shouldn't they have just been able to call to Leo to orb to them when Prue was first hurt, and heal her in the park, and save driving back to the Manor and risk Prue dying?
Plot hole: Lee and Dawn overstay their tourist visa in the US, then fly back to the UK for the Office Christmas party. They then get into a taxi to go out to the airport in order to return to the US. They're kidding themselves. As I know (to my cost) when you overstay a tourist visa, the US Immigration Service finds out when you check in at the airport on departure. They'll be refused reentry, and probably barred from entering the US for up to six years. (I got a three year ban.) Neither Lee nor Dawn could possibly be unaware of this nor think they could beat the system as they would have been arrested when they checked in in Florida on departure (as I was), and they would have remained in small holding cells until the paperwork banning their return had been processed and their passports stamped 'Invalid for U.S. Entry', as mine was. (All this takes about seventy two hours, so they'd have missed the Christmas party anyway.) The mistake is NOT that they were able to leave the USA - that is explained (it's still not possible, but in the context of the show and the suspension of disbelief we are meant to believe it) the mistake is that they are on the way back to the airport to return. That's absurd. They would have been under no illusions as to their banned status re reentry to the USA.
Plot hole: When Zach Young's grandfather died, Zach was said to be the sole heir of the fortune. However, Noah Taylor (the grandfather) had a daughter that appeared several times while Mike Delfino was looking for Deirdre. Where was Kendra Taylor while Zachary Young was spending Noah's fortune on dresses for Gabrielle Solis? Why didn't she claim her share? She simply disappeared.
Plot hole: When Dominique is on TV, she says she got the shoes from Al's store. Then the Amish guy comes out to confirm she broke her leg from the shoe he made. Al says yes. She got the shoes way before Al knew he had no more shoes and before they even hired the Amish guy. How can she break her leg from his shoe if he wasn't hired and making them yet?
Plot hole: Fletcher and Warren steal what they think is the History paper so Godber can study it before he sits the exam. They are adamant that he has a very short time to go through it as they have to put it back before anyone misses it. After Godber refuses to cheat by reading it Fletcher berates him, throws the paper on the cell floor and storms out. What happened to replacing the stolen exam paper?
Plot hole: They're in the Clam complaining that they can't drink when they make the revelation that Brian can because he's technically 56. But Quagmire should be able to drink, as in a much earlier episode, he's revealed to be over 60.
Plot hole: In this episode Arthur scams Deacon and several other parents for phony piano lessons because he doesn't actually know how to play the piano. However, earlier in the series (Art House episode, S1 - E24) we learn that Arthur can play the piano when he temporarily moves out and after his house warming party Doug says to Carrie, "Who knew Arthur could play the piano like that?"
Plot hole: The scientist yells for Igor to capture the escaping Castaways, to which Igor responds "capture them yourself" in Ginger's voice. The scientist appears surprised to find out Igor is not Igor, but how can this be? He had to be the one to pull the lever to switch everyone's personalities and bodies around, so he should have already known.
Plot hole: In Series 1, Episode 7, "The Dumpling Paradox, " Sheldon makes an oblique reference to his financial status: "Frankly, if I could afford the rent, I'd ask you [Leonard] to leave, " meaning he cannot pay the rent on his two bedroom apartment by himself - not that he doesn't want to, he can't. However, in "The Execlsior Acquisition, " we find that he does not even cash his pay cheques. He doesn't even deposit them into a bank account - he leaves them in a drawer in his desk. In Series 2 Episode 14 "The Financial Permeability", he lends Penny a large amount of money from a huge bankroll he just happens to have lying about - again, without cashing his pay cheques! He is obviously independently wealthy. Either he doesn't have enough money to afford the rent or he has enough to work without being paid while practically giving large amounts of cash away. Can't be both.
Plot hole: In this episode Carrie runs into Aidan, who now has what looks to be about a 6 month old baby (Tate). This doesn't seem possible, as Carrie and Aidan would have only broken up about a year ago, and Miranda was around 6 months pregnant when they broke up. Brady is only about 5 months old at this point in the series, leaving Aidan only roughly 8 months to have this baby - but Aidan lay in bed for about a month and then dated Nina Katz for awhile. Timeline just doesn't seem to fit.
Plot hole: In "Pranks A Lot", Patrick and SpongeBob scare Sandy. When Sandy runs, gets into her rocket and flies away. When she moved bubbles appeared meaning there's water in her tree house. There's no water in there in other episodes because she's a land animal and breathes air.
Plot hole: In this episode all the students say Hollywood Arts has never had a prom before. But in the first episode, 'Pilot', Rex says to Cat after she runs out to tell Tori, Robbie, Andre and him that Sikowitz wants them to come back into the classroom, "Just like you wanted a date to the prom last year."
Plot hole: Throughout the show it is reported several times that Billy and Ally met when they were both eight years old in a park by sniffing each other's bottoms. However, when Billy is buried in season 3 his tombstone reads, 1968-2000, making him 32 years old. Ally is only 29 and does not turn 30 until later in that season which would at the very least, put them 2 years apart. (00:41:15)
Plot hole: When Jesse and Michelle wake up in the morning, you can see that the picture Danny got was behind the couch, resting on the seat in the alcove. Later, when Danny goes into the living room and screams, Shorty is standing in the middle of the room, with his head in the picture, and the picture is facing the family. There is no way that the donkey could have put his head in that way.