Continuity mistake: When Francine goes to grasp the bottle of wine she was saving, the first one "told Klaus to shut up" has a cobweb on it. When she goes back to get it, there's no cobweb.
Continuity mistake: After the last school day has ended, Stan chases Steve into a canyon Terminator 2 style to show him camp brochures. After Steve has a go at Stan about not wanting to go to camp, Francine enters the scene, knocking Stan's car out of the way. The car is almost ten meters away from Steve and Stan as she enters the scene. Francine doesn't move the car in the next shot. But in the next shot after that, the car is suddenly right next to Steve and Stan. (00:01:15)
Failure Is Not a Factory-installed Option - S2-E3
Audio problem: Stan looks out the window whilst being suspended from work. As he looks he sees two people exiting their homes and they both say "Bye buddy" and "See ya pal." Their mouths don't move.
Chosen answer: It is just the decision of the creators to do so.
MasterOfAll