Continuity mistake: When Doug, Carrie, Deacon and Kelly are looking at the damage caused by the accident, the same kid in the black and red hat checking his watch walks by twice. (00:05:10)
Continuity mistake: At the accident scene when Deacon asks to have a picture taken with him and Doug, the same couple walks by three times. (00:05:30)
Continuity mistake: When Spence and Kirby are talking about why Spence can't make him a PB&J sandwich, the way Kirby holds the red action figure keeps changing. (00:06:15 - 00:06:55)
Continuity mistake: When Doug, Carrie, Deacon and Kelly are at Coopers, the man in the blue shirt who is talking to the women sitting at the table behind them appears, disappears, walks off and then reappears again during this scene. (00:08:20 - 00:10:40)
Continuity mistake: When Doug, Carrie, Deacon and Kelly are at Coopers talking about the auto-repair bill, Carrie's menu instantly switches from on the table to in her lap and then continues to switch depending on the shot. (00:08:30 - 00:09:10)
Continuity mistake: When looking at the quote for the repair bill, its position on the table in relation to Kelly's menu is constantly changing. (00:08:40)
Continuity mistake: The way Carrie is standing and holding the banana and pop-tart changes as Doug admits that he was trying to look into the strip club, not reaching for a Fig Newton. (00:15:15)
Continuity mistake: When Deacon is asking Doug if "Chain of causation" is a legal term, him arm goes from straight to bent between shots. (00:17:20)
Continuity mistake: After Spence and Kirby's arm wrestle, the way Spence holds the action figure keeps changing between shots. (00:51:10 - 00:51:55)
Continuity mistake: When Kirby says that Spence is scared of peanuts and calls him "The Scaredinator", his hands are empty and his arms are folded - then in the next shot he is instantly holding the red action figure again. (00:51:40)
No Retreat - S4-E5
Continuity mistake: During the opening scene in the backyard, Deacon finishes his beer and puts it down. In the next shot of Deacon he is holding the beer again. (00:00:10)
No Retreat - S4-E5
Other mistake: In the opening scene when Doug is cooking hotdogs for his friends, the smoke coming from the BBQ is very fake. (00:00:20)
No Retreat - S4-E5
Continuity mistake: When Doug tells Carrie at the start he is telling his jet ski story, the tongs he's holding swap hands instantly. (00:00:45)
No Retreat - S4-E5
Continuity mistake: When Horseback riding Doug is holding on to the straps with either one or two hands depending on the shot. (00:16:50)
No Retreat - S4-E5
Continuity mistake: When horseback riding, the track behind them is constantly changing. For example, when Doug hits the tree, the tree then vanishes. (00:17:40)
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: 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)
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)
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)
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.