Petergeist - S4-E26
Continuity mistake: When the spirits first come out of the TV, notice the wall beside the TV. There's nothing there. Brian says who's here? Next shot shows a filing cabinet with a pink blanket on top.
Factual error: Joe's plan to trick OJ into confessing to the 1994 murders is moot since, having been acquitted, the double jeopardy provision would prevent him from being tried for the same crime twice, and as a cop, Joe would know that.
Suggested correction: The plan to get OJ to confess had nothing to do with getting the confession, so he could be arrested or tried again. And at this point, the civil trial already found OJ "responsible" for the murders. Since OJ has always maintained his innocence, getting a confession on tape would just be big news.
Continuity mistake: During the song number when Mr Weed arrives, Stewie has a solo part as he starts to backwards crawl up the stairs. In one shot, he climbs up to the third step, but when the camera changes angles he is only on the second step.
The Kiss Seen Around the World - S3-E8
Continuity mistake: When Meg is given the note in class by Neil saying "I Want You" the letters become much smaller in the second shot as she turns to look at him.
Continuity mistake: When Stewie is thrown from the swing and lands in another little girl's stroller, the inside is suddenly much larger after Stewie lands in it when the camera changes angles to how big it was when he was flying towards it. It suddenly has enough room for Stewie to be lying beside the girl with room to spare while she is still in the center, when it was barely big enough for her alone before he landed.
Ocean's Three and a Half - S7-E7
Factual error: There's no way that Joe and Susie wear the same size diapers.
Stewie, Chris & Brian's Excellent Adventure - S13-E7
Factual error: They all go back to 1912 in London. When Stewie gives a street performer money, Brian informs him that the person wasn't Charlie Chaplin but in fact, Adolf Hitler, and he was right. Back in 1912, Hitler was living in Vienna, Austria and was poor after failing to get into art school. He didn't actually leave the country until 1913 when he moved to Munich, Germany. (00:10:20)
Factual error: You cannot get paternity test results back in one day. It takes 3 to 5 days or even weeks depending on the lab.
Factual error: Peter is posing as a blow up sex doll. The tester picks him up like he doesn't weigh anything. Not possible.
Continuity mistake: Peter falls from the roof of the Clam landing on Joan Cusack. He puts her body in a mailbox that appears just for this scene.
Road to the Multiverse - S8-E1
Other mistake: In every universe - except for the double-headed universe - Brian and Stewie travel to, they (seem to) replace the version of themselves that universe already has of them, but then in the Dog universe they have a separate version of themselves that they continuously interact with.
Ocean's Three and a Half - S7-E7
Factual error: Bonnie changes Susie and Joes diaper. There's no way Joe wears the same size diaper as Susie.
Boys Do Cry - S5-E15
Other mistake: Towards the very end, they automatically head to the car, planning to leave Texas, without any of their items from the house packed in the car after running away from the mob at the Miss Pageant Contest.
