Continuity mistake: When the family leaves for the basketball game Peggy brings the wrong foam finger (not the basketball one) so Hank turns around to get it. It shows him walking into the house, finding it but also finding what he thinks is laundry all over the floor. He also hears what he thinks is innocently the washer or dryer running. He follows the noise towards the kitchen, slowly opens the door to find his mother and Gary presumably having sex on the kitchen table. The problem here is that the kitchen has no door. From inside the kitchen in any episode it is never visible. I checked and further into this episode while opening presents it shows an entrance to the kitchen from the living area where Hank entered and there is no door on that side either. In truth it is an open doorway.
Continuity mistake: The sliding glass door at the Hills' house leads into the kitchen. On the wall next to the door is the chore list and a cutout of the state of Texas, and sitting on the floor is a trash can. There is also no sign of the kitchen table which sits right inside that door as well. Sometimes a trash can is there, etc. When Hank storms out of the house while rest of the family is opening presents, there is a shot when Peggy comes out after him and it shows back inside the door. Instead of what is normally on the wall to the right if you were looking from the outside in, you see a small dresser and all the wall looks to be either a picture or a mirror.