Continuity mistake: Brian insults Stewie about the water and there is a water glass by Bryan's plate. Then it cuts to a shot of Stewie and Chris, and the glass is gone.
Continuity mistake: When Stewie is golfing and spots Brian in disguise, Stewie has a putter. When Stewie realizes that it is Brian and goes after him he is holding a chipper.
Continuity mistake: During the Star Wars rip-off at the end, just before Peter climbs the Town Hall stairs, the people on the sidelines change. (00:19:45)
Peterotica - S4-E24
Continuity mistake: After the Quahog Creek clip is over, they show a picture of the house. In the background there is a tall silver building that wasn't there the last time they showed a shot of the house. (00:17:45)
Continuity mistake: When Stewie has chicken pox the red marks on his face change position many times between shots. A noticeable one is just as he is saying "No, damn you, I've got to finish what I started".
Continuity mistake: When Chris hides the vodka from his teacher, he holds his right hand behind his back with his left arm at his side, but in the next shot, both his hands are behind his back. (00:09:40)
Continuity mistake: When Peter walks away from Brian with the hula hoop around his waist, he runs into the stereo, knocking a vase of flowers on the floor, shattering the vase. Next shot shows the mess cleaned up without anyone even cleaning it. (00:04:45)
Continuity mistake: When Stewie and Bertram are parachuting down to Earth after the air strike, their parachutes get much closer to each other between shots. This occurs just before they start slapping each other.
Continuity mistake: When Lois turns on her parents' bedside lamp, it only casts a small beam of light onto the floor, but later in that scene, the same beam of light is much bigger. (00:06:15)
Continuity mistake: When Stewie pushes Brian down the stairs, in the background at the moment he pushes him that the stairs are visible behind Stewie as well.
The Father, The Son, and The Holy Fonz - S4-E18
Continuity mistake: When Francis arrives, he changes from standing on the threshold to standing inside the house, even though he could not have moved between shots. (00:01:30)
Continuity mistake: The interior of the Griffins' bathroom changes color (from yellow to blue), when Chris first talks to his pimple.
Peterotica - S4-E24
Continuity mistake: When Peter is reading Lois his erotica in bed, the size of his paper changes just after he says "his really cool spaceship".
Continuity mistake: As Brian is saying "OK, you know what, fine, you are a genius", the glass of water disappears. (00:05:55)
The Father, The Son, and The Holy Fonz - S4-E18
Continuity mistake: When Francis is standing on a chair, nailing the crucifix above the door, the bottom of the crucifix overlaps onto the door frame, but when Francis comes down from the chair, the bottom of the crucifix is above the door frame.
Continuity mistake: When Chris is sitting on his bed talking to Doug, the squares on his quilt pattern get smaller. (00:15:05)
Continuity mistake: When Peter is giving the team steriods, the syringe always goes back to the same place.
Continuity mistake: Just after Lois decides to get rid of Chris's pimple, the pimple changes position in relation to Chris's hair. (00:09:30)
Continuity mistake: When Peter and the rest are at the bar and Quagmire is telling Peter that he looked through his garbage, Quagmire's mug tops up between shots.