Continuity mistake: At the start, the distance the canoe has drifted changes instantly. And it changes a huge distance. (00:04:20)
Continuity mistake: When Arthur asks Doug for a game of ping pong, the paddle is lying flat on the table. In the next shot there is a ball under the paddle which Arthur picks up (The ball is still on the table). In the next shot the paddle is back on the table and the ball is missing. (00:03:15)
Continuity mistake: When Arthur asks Doug for a game of ping pong, a ball suddenly appears under his bat and then disappears and Doug throws him the ball to have the first serve.
Continuity mistake: In the scene where Spence is entering the place his girlfriend works, he is pushing the door in. When the camera angle switches he is pulling the door open.
Continuity mistake: Carrie says that Deacon does not "drink or smoke." Previous episodes have shown him drinking beer with the guys. Also, in the episode "Friender Bender", it was mentioned that he drank a margarita during dinner at a restaurant.
Continuity mistake: Doug goes to Deacon's to tell him about Kelly wanting to get back together. Deacon is putting on his shoes and in different shots, sometimes his shoe is almost on and then other shots it shows him holding it in his hand about to put it on again.
Continuity mistake: While Arthur tries to convince Spence about the card, when Spence bites into the fake cookie he's holding it in his left hand and holding the plate in his right hand, but in the next shot facing Arthur the items have switched hands. (00:16:30)
Continuity mistake: In this flashback episode, when Doug is shaving his mustache and talking to Deacon by his locker at IPS, Danny Heffernan's name can be seen on a locker. At this time, Danny was not working at IPS.
Cheap Saks - S6-E15
Continuity mistake: At the art gallery, the way Doug is holding the program instantly changes a couple times; arms crossed/uncrossed, program folded/unfolded. (00:02:20)
Cheap Saks - S6-E15
Continuity mistake: Near the end of this episode, after Trish Flintoff leaves, Doug is telling Carrie and Holly that she's a nice person. Doug is looking at Carrie, then the shot changes and he is immediately looking down and reaching towards his back pocket. It also looks like he's trying not to laugh. (00:19:35)
Continuity mistake: In the scene where Doug's father is shutting off the alarm, he does not enter 2965. We know this is the proper code, because it is Doug's birthday, and it worked when he entered it. It looks like he maybe enters 1459.
Continuity mistake: Carrie says that she "didn't go" to college because Arthur felt that she would be abandoning him. He points out that her mother had just died. According to the episode "Class Struggle" (Season Two), Carrie actually went to college and then her mother died, causing her to drop out. In that episode, she wants to "go back" to college.
Tank Heaven - S6-E21
Continuity mistake: In the scene where Danny has just taken the "nucleus" nacho chip, after Carrie walks in, the chip in Danny's hand keeps changing between shots, then disappears altogether almost instantly and his arms are folded when he begins his next line. (00:02:30 - 00:03:25)
Continuity mistake: The second time we see Doug's disk, it is spinning. In one shot it is spinning in shadow, but in the second shot it is in the sunlight. (00:08:00)
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.