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 Arthur's friend Mr. Glassman comes into the Heffernan house, a large tree can be seen on the front lawn, which we know from many other episodes there is not a large tree in front of the Heffernan house. (00:09:30)
Visible crew/equipment: When Doug is sitting in the living room and Carrie comes into the kitchen carrying groceries, a boom mic shadow is seen moving on the wall behind her. (00:04:10)
Continuity mistake: At the dinner table while talking about being obscure at work, Doug starts pouring his beer into a glass. But immediately in the next shot he is finished pouring and both bottle and glass are on the table. A moment later he picks up the beer and pours it into the glass a second time. (00:03:45)
Visible crew/equipment: When Doug is talking on the phone, the shadow of a boom mic moves on the wall behind him. (00:00:20)
Affair Trade - S9-E2
Continuity mistake: When Doug and Jessica run into Carrie in the parking lot at the Dr. Heffernan office, there is a man walking up from behind them with grey hair. In the next shot he instantly appears beside them unrealistically fast. (00:19:20)
Frozen Pop - S2-E15
Continuity mistake: When Doug and Carrie wake up covered in sweat, the position and amount of blanket on Carrie changes just before she pushes the covers off and gets out of bed. (00:04:50)
Continuity mistake: In the exterior shot of Coopers there is a car parked, no bins, no people. However, in the immediate interior shot, you can see a garbage bin, newspaper box and people walking by in either direction. (00:13:15)
Continuity mistake: When Ritchi and Spence are at the cafe, Spence pours the remainder of the pitcher into his cup. The shot goes back to him, and it appears he took a large sip because his cup is near empty. When Doug and Deacon come in, Spence's glass is almost full again.
Continuity mistake: When Doug has just shot himself and Carrie calls him at work, he looks back to Deacon before answering the phone. On the platform behind Deacon, a woman IPS employee appears instantly. Also, the IPS staff walking behind them do not match between shots.
Continuity mistake: Doug and Carrie are fighting in the kitchen. Around the time that Carrie says, "I give you one thing and you screw it up," Carrie's handbag in the background is standing upright. The shot goes back to Doug. When it goes back to Carrie and she is leaving, she picks up her handbag which is now no longer upright. Her handbag also looks like it has been shifted.
Dire Strayts - S2-E8
Visible crew/equipment: When Carrie storms out into the back yard, Doug follows. When he does, the kitchen door stays open and if you look at the glass it reflects all the stage equipment above the set in the kitchen. (00:07:00)
Frozen Pop - S2-E15
Continuity mistake: When Doug has just gone back to bed and Arthur walks in, Doug's position on the bed changes instantly. He swaps sides. (00:05:35)
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.