Continuity mistake: Doug gets into a mess with the sellotape wrapping Carrie's Christmas present. However when she walks downstairs it's on the table, absolutely fine. (00:02:20)
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)
Mean Streak - S4-E3
Continuity mistake: When sat at the table at the start, the bottle top keeps changing position in relation to the edge of the table. (00:03:00)
Continuity mistake: When Carrie finds Doug in the kitchen in the middle of the night, her arms are crossed with her hands tucked into the sleeves. After she asks him about his pay check from IPS, the shot changes and her hands are now on her hips. (00:10:50)
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: 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)
Revealing mistake: During both opening and closing driving scenes, a light on the back and top of Doug and Carrie's heads slowly flickers on and off but never moves - revealing a stage light simulating driving past street lights. (00:00:20)
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)
Continuity mistake: When Doug puts down the remote to grab Carrie's Walkman, the position of the remote changes between shots. (00:00:45)
Food Fight - S4-E13
Continuity mistake: When Arthur tells Doug to eat some salad he is either holding the bowl or not depending on the shot. (00:18:40)
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.