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.
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.
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.
Not All Dogs Go to Heaven - S7-E11
Continuity mistake: While Meg is at the kitchen table telling the family about her new life with God, you will notice that Brian is sitting to the right of her. As she starts to ask that everyone hold hands, take notice that Brian is not in that chair and that Brian's plate and utensils are moved closer to Meg. As the shot pans out, Brian is back in that chair.
Factual error: Brian is sitting on the couch smoking weed. Joe knocks on the door and Brian just waves the smoke from the air. Joe is there to give Brian a drug test and says nothing about smelling weed in the air. There's no possible way he didn't smell it! You can't just wave your hand and get rid of the smell.
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 gets beat up and thrown in to a black limousine by hired thugs of Mr. Pewterschmidt. While in the car, notice that as Peter starts talking to Mr. Pewterschmidt that there is no cart of Diet Rites next to him. Next shot there is. Then the cart disappears as Mr. Pewterschmidt tells Peter what is on his mind.
Stew-Roids - S7-E13
Continuity mistake: When Lois is talking to Meg on her bed she gets up and throws a book and a bottle of pills on the bed that came out of nowhere. The nightstand is out of view but if you look at the earlier scene there's nothing on the stand except a clock and a lamp.
Three Kings - S7-E15
Factual error: Stewie shoots Joe with a double barrel gun. He shoots at him 3 times without reloading. (00:12:50)