Plot hole: Stewie gets out of the car seat and goes back to bed, leaving the blanket at the bottom of the seat. When they get to New York, Lois goes to get him out and realises he's gone. But when they started the trip the blanket was covering the entire seat to make it look like Stewie was still in it. So who ever "covered" him up knew he wasn't in the seat before they set off. (00:13:45)
Continuity mistake: After getting the uranium, Stewie places it in the time pad and then puts the pad in his jacket pocket. After being confronted by Hitler who promises to spare them if they sing a musical number, Mort interrupts them, and it's seen that he is now standing on the time pad.
Continuity mistake: After Conway Twitty finishes his song, the scene cuts back to Perter and his family at the kitchen table. Take notice that Lois is sitting next to the back door, and Brian is sitting next to the kitchen sink and window. Keep an eye on that kitchen sink, window and door, because it will be replaced by a yellow wall with the telephone now being closer to Lois. Later as Lois, Brian and Peter are discussing OJ Simpson, the sink, widow and door return.
Not All Dogs Go to Heaven - S7-E11
Continuity mistake: In the part where Meg is asking Brian about God, and Brian answers he is an atheist, the camera pans out quickly, and we see an entrance to the kitchen with an air vent above it. Eventually the family discussion with Brian continues, and you see that the air vent is now gone.
Ocean's Three and a Half - S7-E7
Continuity mistake: Before Dr. Hartman delivers Bonnie's baby, he removes a small wheelchair and places it on a cabinet next to him. After delivering the baby, he makes a funny remark about Paula Poundstone, and then he hands the baby to Bonnie. Notice that the wheelchair and the cabinet are no longer present.
The Man with Two Brians - S7-E5
Other mistake: Brian puts in a video tape of him as a puppy. But he hasn't been with the Griffins since he was a puppy. Peter picked him up from the street as a homeless adult dog.
Ocean's Three and a Half - S7-E7
Continuity mistake: Bonnie gives birth to Susie. After she is born, she's completely bald. In the next scene, Bonnie is at Peters' holding her and she has a full head of hair, complete with a bow.
Revealing mistake: At Warsaw Temple, when Mort says "my bargain hunting Aunt Flo", production initials appear next to Brian's tail.
Continuity mistake: When Mort runs into Stewie's room, thinking it's the bathroom, there is a sign on the door that reads "Stewie's Room - Keep Out Brian." But a few moments later when Brian enters the room looking for Mort, the sign has disappeared.
Ocean's Three and a Half - S7-E7
Continuity mistake: As Joe is waiting on Peter, Quagmire and Cleveland at the bar, take notice that he is holding a tray with two bottles of beer on it. One bottle is sitting behind the other in the close up shot of Joe. However when the shot pans out, you see that the bottles are side by side.
FOX-y Lady - S7-E10
Continuity mistake: As Peter is selling his cartoon idea to Mr. Chernin at Fox, you can see a small globe behind him. After the cartoon is shown, and the shot returns to Peter and Mr. Chernin, you will notice that the globe turns into an Emmy award.
FOX-y Lady - S7-E10
Continuity mistake: When Fred Savage takes off his Rush Limbaugh costume, he throws the clothing on the floor. Lois and Brian jump through the window to confront him, and the clothes are in new positions on the floor.
Continuity mistake: Toward the end of this episode, Stewie is at home in the living room talking to Rupert about how depressed he is about being alone. All of a sudden he hears his family come back home, so he gets up from the couch and runs to the window leaving Rupert on the couch. As soon as Stewie moves his head away from the window take notice that Rupert is no longer on the couch.
Continuity mistake: When OJ Simpson first meets Peter for their game of golf, both Peter and OJ have only four irons and a putter in their golf bags; however, when OJ tees off, he does so with a wood.
Factual error: In the bit when Brian and Stewie are in Poland, the sign they are looking at should say Warszawa, not Warsaw.
Continuity mistake: As Peter makes a comment on Jesus' joke, the screen goes into a closeup between the two of them. The potatoes on their plates change from a sandy yellow to white and the next time their plates are in view, the potatoes are back to their original colour. (00:11:33)
Continuity mistake: When Mort goes into Stewie's room, there is a sign on the door that tells Brian to stay out of his room. A few minutes later when Brian and Stewie enter the room, there is no sign on the door.
Factual error: In the park, Stewie and Brian are playing the "water pipes" like a xylophone. Trouble is, in order to get the tones they were playing, the glasses should have had different levels of water in them. If you look closely, all the glasses have the same level of water.
Continuity mistake: Peter is sitting in the audience with a blue jacket on. Next scene shows him come out of the building not wearing the jacket.
Family Gay - S7-E8
Continuity mistake: Just before Peter tells Chris he is the man of the house, he is standing with his arm around his partner Scott's back standing in front of him. Next shot, he is now standing even with Scott, 90° more turned to Chris.
Answer: Lacey Chabert was the actress who originally voiced Meg in early episodes. She left of her own accord due to being in school and other acting work; Seth MacFarlane has stated there was no tension with her leaving, but it makes for a handy joke for the show.
Jon Sandys