Continuity mistake: During the scene where Gaby and John are in her bedroom talking, she takes a drag from her cigarette while John asks why she isn't happy, but never exhales the smoke from that drag. 23 seconds pass from that drag to the next one and she's in frame the entire time (it cuts between shots of the two of them together and Gaby's close-ups, but doesn't cut away from her). It's also worth noting that Gaby is never seen smoking again at any other point in the series and no explanation is given as to why.
Continuity mistake: When Lynette is in the supermarket, right after she loses track of the twins, she is seen pushing her shopping cart down the aisle,and in the seat there's only a pink blanket. But when she sees Nelly Klein, her baby daughter is sitting in the seat with the blanket and one of her sons is riding in the basket.
Continuity mistake: Season 1, episode 1 (Pilot): While Gaby and Carlos are arguing in their house, we can see a sofa and some other items in a semi-circular alcove with five tall windows on the far wall of the front room, and a painting near the stairs. A minute later, Carlos leaves and Gaby is alone with John, and the room has changed drastically. The alcove is now a flat wall with two windows and a fireplace. The sofa and some other things are missing and the painting moved to above the fireplace. This inconsistency exists because after the pilot was filmed, the set was redesigned and the part of John Rowland was recast. The scenes with John were reshot after the redesign took place, but the majority of this episode, including the first half of this scene (the argument), used the original footage.