Continuity mistake: The vent-hood in the kitchen above the stove/island is always disappearing and reappearing. Sometimes it's there, sometimes it's not. The handles on the fridge/freezer also keep changing sides. Sometimes they are on the left, sometimes they are on the right. And the living room is always changing sizes. Sometimes they open the front door and the couch is right there, and sometimes it's several feet away from the front door.
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)
Continuity mistake: Steve, Hayley and Francine all stand next to the door when Bullock arrives. They are all standing right next to the door in the shot where Stan adjusts their clothes. But they suddenly move a couple feet away from the door in the following shot where Stan opens the door. (00:03:45)
Continuity mistake: When the bus driver finds Roger, the Dignity Towers Retirement Home bus is only a few feet away from them. But in the shot where Roger says "How do I get home? How do I get home?", there was no sign of any bus for many many meters. As if the bus just appeared out of nowhere. (00:09:45)
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)