Visible crew/equipment: When Holly walks in at the start, a tape marker is visible on the floor. (00:09:10)
Visible crew/equipment: When Arthur comes out the basement singing Silent Night, he stops and waits a few seconds while trying to remember the next line. Carrie prompts him for this and he thanks her and walks off. As he does, the camera changes angle and a tape marker can be seen on the floor where he stopped to remember the next line in the carol. (00:03:30)
Visible crew/equipment: When Doug and Carrie are talking at the start, the green and red baubles give a nice reflection of the stage lights. (00:02:25)
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.