Continuity mistake: When Stewie is in the sterile glass cage, Lois is changing his diaper with rubber gloves built into one of the panels (like Homer Simpson's in the opening credits). In previous and subsequent shots, however, the panel is solid glass, with no gloves. (Series 4: The Father, the Son, and the Holy Fonz).
Continuity mistake: When Karen Black is first shown, her blue uniform is sleeveless, showing her white shirtsleeves. After a cut to the "Dawson's Creek" kids, Peter says "It was a movie in the seventies," and Black's outfit has sleeves. Later, when she is helping people off the plane, her uniform once again is sleeveless.
Factual error: At the end of Peter's trombone solo, he holds out his last note. While holding the note, he moves the slide with no change to the note whatsoever. Since the pitch of the trombone is controlled by the slide, it would be impossible for Peter to move the slide as much as he does without changing the pitch he's playing.
Continuity mistake: When we first see all the guys at the NAAFP meeting, there are two guys in the top right corner; one with a singlet and one with brown hair and a green-brown T-shirt. In the next shot, these two guys come in from the opposite side of the screen.
Continuity mistake: At the bottom of the stairs there is a picture of Peter and Lois, and the song "So Long, Farwell" starts. The kids start singing and you can see in the backround the picture is gone then comes back when the kids are going back up the stairs.
Continuity mistake: Just after Patrick 'kisses' his imaginary girlfriend goodbye and tells Brian to look after her, Brian switches position on the couch. In the first shot he is sitting on a crack between couch pillows, but in the next shot he is sitting in the middle of the centre pillow.
Other mistake: When Quagmire is sticking his body out of the car door and yelling "Whooooooa! Whoooooooa!", look at the person in the back seat. It certainly isn't Joe, who was there in the previous shot, in fact it looks like another Quagmire.
Continuity mistake: In this episode, Mort Goldman shows Peter a dating video he made, saying it's how he and his wife met. He is an adult in the video, yet in an earlier episode 'The Kiss Seen Round The World', Mort's wife tells the Griffins that she met him when they were just 14.
Continuity mistake: When Ulysses S. "Griffin" is chugging beer with Robert E. Lee, Ulysses wins. When he says "How's that Robert E. Lee," he puts the beer glass on his head. After Robert says, "Okay no more slaves, but we still don't have to read books," the glass is in Ulysses' hand. In the next shot it's on his head again.