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)
Visible crew/equipment: After Doug gets Arthur out of the house he takes him to a restaurant, and as they both take their seats, the two sets of double tape marks are visible on the carpet under the table. Then, when Doug stands up another small tape mark is visible at his feet. (00:06:30 - 00:08:00)
Visible crew/equipment: When Doug and Arthur are eating in the buffet restaurant, stage lights are seen reflecting in the cup. Also, each time the camera goes from angle to angle, the cup has moved from one side of the table to the other, sometimes have a saucer, sometimes not. (00:06:35 - 00:08:20)
Continuity mistake: When Doug and Arthur sit down to eat, the cup that is on the table is either by Arthur or by Doug depending on the shot. (00:06:35)
Continuity mistake: At the buffet, the cup that is on the table is either on or off a saucer depending on the shot. (00:06:55)
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)
Continuity mistake: When Doug is going into the living room after Carrie has gone in search of Arthur, his left hand is on the door. When he goes through the door, he is opening it with his right hand. (00:14:00)
Visible crew/equipment: When Carrie and Arthur pull into the driveway, the camera is reflected in the car. (00:18:15)
Revealing mistake: When the lights go out at the end of the episode, there is a reflection from a stage light very visible. (00:20:30)
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.
Wild Cards - S2-E20
Factual error: Deacon is holding an In-N-Out drink cup. In-N-Out is a burger chain only located on the West Coast of the United States. (00:02:00)
Big Dougie - S2-E21
Revealing mistake: When Doug is jogging in the marathon he is casting three shadows in different directions. Also, the female jogger behind him appears to be in good shape but is still jogging as dramatically slow as Doug. (00:19:20)
Soft Touch - S2-E22
Visible crew/equipment: At the start, in the shots facing Carrie and Doug while they're in the car, we can see a screen atop the roof on the driver's side of the car with its reflection on the windshield (and its shadow on the car's hood). This is gone in the overhead long shots. (00:00:10)
Soft Touch - S2-E22
Continuity mistake: At the start, when Carrie is trying to park, the same clip is shown. The same people walk by. (00:00:30)
Soft Touch - S2-E22
Continuity mistake: At the beginning, when Carrie is trying to park the car she's wearing a 3/4 sleeve blue top in the closeups, but in the overhead shot of the car for the last attempt when Carrie says that she's cutting it, the driver is not wearing that blue top, the driver is wearing a plaid shirt. (00:01:00)
Soft Touch - S2-E22
Visible crew/equipment: When Doug and Carrie go to get up from having dinner with Saskies, tape markers are visible on the floor by their chairs. (00:05:30)
Soft Touch - S2-E22
Continuity mistake: When Carrie is asking Doug why he likes it at the neighbors, her arms are on her hips. Camera cuts and now they are straight down at her side. (00:08:40)
Soft Touch - S2-E22
Continuity mistake: When Doug and Carrie are arguing about selling filters, the bed covers keep changing place. Note the position in regard to the jeans. (00:09:05)
Soft Touch - S2-E22
Continuity mistake: When Doug is getting into bed while talking to Carrie about selling water filters, his grip on the duvet changes instantly. (00:10:00)
Soft Touch - S2-E22
Continuity mistake: When Doug is asking Carrie about the water, she puts a glass down and the level of water in both glasses is significantly different. Camera cuts and they are level. (00:11:10)
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.