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)
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)
Continuity mistake: When Arthur and Spence are talking in the kitchen, a fork keeps appearing and disappearing from Spencer's plate. (00:05:40)
Continuity mistake: When Doug and Carrie are talking about the fact the workmen have actually turned up, the cup on the table keeps rotating with no-one touching it. (00:12:15)
Continuity mistake: When the Marshall is chasing after Doug the distance between the two changes drastically. (00:16:00)
Continuity mistake: When Doug is being a polar bear, the bag Carrie was looking in disappears. (00:08:00)
Continuity mistake: When Tim and Doug are talking about the pool overlooking the property, the way Tim holds the ball changes between camera cuts. (00:15:00)
Visible crew/equipment: When Doug gets the beach ball, all the stage lights are reflected in it. (00:14:00)
Continuity mistake: When the guys are having brunch, Kelly has got her mug in her hand. Camera cuts and her grip has changed on the mug completely. (00:06:40)
Continuity mistake: The Heffernans have neighbors on both sides of the house as seen in previous episodes. However there is no house to the left of theirs when we see Lou at the very start. (00:00:40)
Continuity mistake: The Heffernans have a double garage as witnessed in any scene in the garage. However, in this episode at the start they only have a single garage. (00:00:30)
Continuity mistake: When we first see Lou, he is pushing some rubbish down into the bin, camera cuts and he now has a box in his hand. (00:00:05)
Visible crew/equipment: When Carrie notices that Doug has walked out the room, there are some tape markers on the floor from where Doug was stood. (00:09:40)
Continuity mistake: When Carrie say to Doug that they are sleeping on the fold out couch, her arm goes from on her hip to hanging by her side instantly. (00:11:00)
Continuity mistake: Carrie cuts Kirby's burger in half with a knife in her right hand. Camera cuts and a fork has appeared in her left hand. (00:10:30)
Continuity mistake: When Carrie is serving up the burgers for dinner, she places one on Kirby's plate. Camera cuts to Kirby sitting down and the burger has vanished. (00:10:25)
Strike One - S3-E5
Visible crew/equipment: When Carrie is trying to return the truck, there are tape markers visible on the floor. They are little white dots. (00:11:35)
Strike One - S3-E5
Continuity mistake: When in the garage, the way Carrie's arms are crossed changes instantly. (00:09:50)
Visible crew/equipment: When the dummy is on the sofa with Arthur, the stage lights are reflected in its sunglasses. (00:16:00)
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.