Continuity mistake: When Deacon and Kirby are at Doug's the house over street is a mid terraced house in one shot, and an end terrace in another. (00:06:00)
Revealing mistake: When Doug and Deacon are driving round trying to find Gabe's Pizzeria, they get into the car and pull out into the road. However if you look at the traffic, they would have hit at least 2 cars in doing so. But they don't, showing it's a projection. (00:14:40)
Continuity mistake: At the store, Doug picks up 5 or 6 bags of sweets. Most noticeable is 2 yellow bags. Camera cuts and they have disappeared. (00:01:05)
Continuity mistake: Arthur throws Doug's pumpkin out near the start and there is no pumpkin on the floor in the kitchen. A few minutes later in the scene, there is pumpkin on the floor in the kitchen. (00:03:40)
Audio problem: When the nurse compliments Doug on his costume, she taps him on the arm twice. However the sound is out of sync. (00:08:00)
Continuity mistake: The bag Doug puts on Arthur's hospital table is a lot bigger than the bag he got at Gabe's. We know it's not a different bag as he ran from Gabe's, and the bag says Gabe's on it. (00:19:00)
Continuity mistake: When scooping the ice creams for Arthur, Doug scoops pineapple, then banana, from the open case. He then finds lemon, but has to open the case again. (00:17:45)
Continuity mistake: When Arthur is talking to Doug in the hospital, the pillow behind Arthur keeps changing position. (00:11:00)
Other mistake: When Doug is saying that Arthur does nothing that Deacon just listed, there is a camera angle of him walking down the aisle with Deacon. In this camera angle only there is a blip to the top right of the screen. This little black mark stays in shot while the camera is moving and is only in this one angle. In other shots of the same angle the black mark is not present. Clearly something was on the camera lens during filming. (00:05:30)
Continuity mistake: When the doctor is explaining to Carrie what is wrong with Arthur, he has a stethoscope round his neck that keeps changing position between shots. (00:08:30)
Continuity mistake: When the nurse walks away from Doug, she walks away, camera cuts and she starts to walk away again. (00:07:25)
Continuity mistake: When talking about getting a pumpkin, Deacon knocks a toy onto the floor, When the camera moves back you can see the toy has gone. (00:01:30)
Continuity mistake: When Carrie is taking the shopping out of the bag, the items are constantly moving on the side without being touched. (00:03:30)
Character mistake: The Doctor tells Carrie what's wrong with Arthur and what they are going to do. When he tells Carrie this, they are in a packed waiting room, completely violating patient confidentiality. (00:08:35)
Answer: Sara hasn't been mentioned in later episodes, and it suggested in later episodes that she never existed, and that Carrie is an only child. Kevin James stated that the producers couldn't think of an good plots to use with Sara, so they left her out.