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: Arthur grabs a spoon to have some of the brie, camera cuts and he grabs the spoon again. You hear him take the spoon twice as well as it clangs on something. (00:04:15)
Continuity mistake: When they are talking about Carrie only having one good ovary, the napkin under Doug's hand keeps changing position. (00:15:10)
Continuity mistake: In this episode, Doug looks out his bedroom window and sees his parents and Arthur standing on the porch by the front door, but in season one, the episode when Richie sleeps with their neighbor, Carrie and Doug's bedroom window faces the Sacksi bedroom window.
Suggested correction: The window in this episode is the one looking out the front (same wall as headboard), but the one referenced in the episode with Richie is the side window, so a different view.
