After Doug takes the turkey from the refrigerator, he pushes the refrigerator door, but it remains wide open. Carrie enters to chastise Doug, and the door opens and closes between shots.
The flashback to Doug and Carrie's first Thanksgiving was clearly filmed in either spring or summer rather than November. There are plenty of outdoor shots where the grass is green and the trees are full of leaves instead of bare as they should be that time of year.
At Lily and Arthur's house the bathroom window that Arthur speaks to Doug through is in the middle of the bathroom when shown from the inside and on the extreme edge of the bathroom when shown from the outside.
In the pilot of the series it's reveled that Arthur's second wife's name is Tessie. In this episode her name is Lily.