Other mistake: During the Vagina Monologues show, the pair of legs casts a shadow but the microphone stand doesn't. (00:00:45)
Other mistake: When Stewie sneaks into his parents' room and attaches the breastfeeding pump to Lois, he places the cups too high on her chest for them to be on her nipples. You can see this, especially after he removes the cups.
Other mistake: In season 4 episode 7, 'Brian the Bachelor'. Cleveland is sitting in a chair in a waiting room and is getting really nervous. Peter tries to help him by tying him to a chair and when that doesn't work, he takes off all of their clothes. Peter ties Cleveland's hands to the arms of the chair and then takes Cleveland's clothes off. He couldn't have taken the shirt off while Cleveland's hands were tied to something without untying him or ripping the shirt, which he didn't do.
Other mistake: When Lois is saying that she'll make a nice romantic dinner, Chris's picture on the wall not only looks completely different, but he's wearing glasses. (00:08:00)
The Courtship of Stewie's Father - S4-E16
Other mistake: When Mr. Hubert is singing about his fantasy life with Chris, he is reflected in a mirror but his arms do not have the same angle; the reflected one is much steeper.
Other mistake: Right at the start when you get an aerial shot of the bowling alley, there is one that gets a strike. The machine sweeps them away, but the pins still remain. (00:00:05)
Other mistake: When Stewie demands his device, he says, "Like a box of active grenades," and she gives it back. The pins weren't pulled, yet he runs and it explodes. (00:18:00)
The Cleveland-Loretta Quagmire - S4-E5
Other mistake: When Peter is painting the Sistine chapel, he has green paint on his brush, even though the picture is entirely black and white. (00:03:50)
Other mistake: The 'KISS' logo above Kiss's stage isn't actually held up by anything.
Other mistake: When Peter is dancing to his musical number on top of the table, his head continually shrinks until the end of the shot, where his head is around a third of what it was originally.
One If By Clam, Two If By Sea - S3-E4
Other mistake: After the hurricane passes, Peter acts like he's been impaled by a wooden plank. He pulls it out as if it was attached to his right side. However, the way the metal on the clasp was bent, the only way the wooden plank could've been positioned that way is if the metal was over his shoulder.
Other mistake: When Chris is telling Peter that he is out of the scouts, pink can be seen through his earring, even though his earring is in front of his blonde hair, not his skin. (00:06:30)
To Live and Die in Dixie - S3-E12
Other mistake: When Stewie is with his 'band' for the first time when he is tuning his guitar, the string he's tuning doesn't match the peg he's turning.
One If By Clam, Two If By Sea - S3-E4
Other mistake: When the cops burst into the house we see the action on a TV as shown by the Quahog News logo in bottom left. However on the TV in the living room the logo is missing. It should be there as well. (00:12:45)
Fifteen Minutes of Shame - S2-E12
Other mistake: Right at the end, when Peter takes out the Bible, the front cover is on the wrong side, i.e the back.
Other mistake: Peter goes back in time and sees Lois at age 18. Death says everyone will see Peter as being 18 too. Problem: Lois and Peter aren't the same age. In later episodes, Lois reveals she's 2 years older than Peter so Peter should be 16 when he meets Lois.
Other mistake: In the scene where Einstein is stealing Smith's theory, when Einstein pulls the metal bars down, they should land on Smith's head, but Smith inexplicably moves forward and the bars land on his back.
A Very Special Family Guy Freakin' Christmas - S3-E16
Other mistake: When Peter runs over the manger with his car the camel flies towards the left out of shot, but when it falls on Peter it is falling straight down as if it was shot upward.
Stuck Together, Torn Apart - S3-E19
Other mistake: In the scene where Brian gets off the phone with the glue company, he says the bad news is that the substance to remove the glue takes two weeks to arrive, but the captions read seven days.
Other mistake: When Lois knocks out the karate master, if you look in the stands, behind Peter, there is a person without a nose.