Continuity mistake: When Marge runs back to the kitchen to retrieve the wedding video, the house is ablaze. In the next shot, when the mob is carrying the car away, there are no flames visible in the house.
Continuity mistake: In the cinema, when Homer tells everyone how boring this is, behind Bart, Lisa, Maggie and Marge sits Otto, Kirk van Houten and Barny, but in the next scene behind them sits Otto, Jasper, Kirk van Houten and Moleman.
Continuity mistake: When President Schwarzenegger tells Russ Cargill he will have to go back to making family movies, there is a "Diaper Genie" promo poster on the Oval Office wall and on the immediate left of President Schwarzenegger's desk. But the promo poster disappears and the walls of the Oval Office become further from the desk in the next long shots.
Continuity mistake: In front of Krusty Burger, when Lou carries a naked Bart to the sign post, the post is embedded directly in the concrete walkway slab, just beside the left corner of the patch of grass. Once Bart is cuffed, the sign post has actually moved down about 4 feet, and is also now embedded directly in the grass at the right corner. In following shots, it's at the left corner of the grass and then right again.
Continuity mistake: When Homer is grooming Spider Pig he is in Bart's room and it's on the end of the house because you can see the corner of the house, then he walks out of the room and goes in another room but that room is on the end of the house too, you can tell it's a different room by looking in the background so it doesn't make sense that both rooms are in the same place.
Continuity mistake: When Homer and Bart are fixing the roof (near the beginning) there is no tree near Ned Flander's house. Later on Bart is on a tree next to Ned's house talking to Ned Flanders.