Character mistake: When Alex mentions to Mallory that he's had sex before, he tells her he was 17 and that it was leap year. Not correct, this event occurred in 1982 (during one of the first episodes when Alex was 17), which was not a leap year.
Continuity mistake: When Alex tells Jennifer to play her clarinet outside Jennifer complains that its dark out, but you can see through the window that it is bright out. When they show it again it is dark.
Character mistake: When Uncle Ned calls Alcoholics Anonymous, he only dials 6 digits on the phone (instead of 7), but still the call successfully goes through.
Speed Trap - S2-E6
Continuity mistake: When Alex falls asleep after he and Steven are talking in the room about the dangers of the pills, there is an alarm clock on the nightstand next to the bed. Next scene, the parents come in and wake up Alex and suddenly the alarm clock disappears and is nowhere to be seen anywhere around.
Answer: Since they don't have a door there in the living room but they do have a door there in the dining room I assume it leads to the dinning room and the door upstage is probably straight to the living room while the door downstage goes to the dinning room and then through more doors you get to the door in the the living room. Hope that made sense.