Continuity mistake: In the scene where Francine says she used to be friends with everyone in the block, there is a cutaway of a previous neighbor couple called the McLearys. After the cutaway, keep an eye on Francine's coffee mug. The mug keeps changing position on the table between shots. (00:02:10)
Continuity mistake: At the convention when we first see Roger and Hayley, they pass a booth that says Costume contest registration. There is also a few people around, a poster and a movable wall. The very next shot is more of a close up of the two and the background has changed dramatically. There is now about 4-5 different stalls behind them and no sign of the previous one or the poster and wall.
Continuity mistake: In the pilot episode, during the breakfast scene, there are five donuts in the box in front of Roger before his chair breaks. When he takes one from the box, there are eight. When Francine takes his donut away, there are five in the box again. (00:03:20 - 00:03:50)
Continuity mistake: Just as Bullock rings the doorbell, Roger oozes gunge from the left side and right side of his torso. The gunge from the right side goes on the couch and the left side goes off screen in a direction towards the door. Yet when Stan answers the door, no gunge is visible on the floor anywhere. (00:03:25)