After Deacon exhales a big puff of cigar smoke, the air clears instantly.
When the doorbell rings Carrie answers the door and you can see Deacon through the clear glass at the top of the door, Spence and Danny are there also when the door opens. Carrie won't let them in and shuts the door. The shot changes to the outside and the glass at top of the door is no longer clear.
As Carrie is telling the gang to put out the cigars, you can see a jar next to Deacon's right arm. In the next shot there is a can along with the jar.
While eating pizza, Carrie picks a napkin, lays it flat on the table, then wads it in her hand. Next she slaps the pizza slice down on top of the napkin that is now flat on the table and not wadded in her hand. Doug then picks up the slice off the bare table top and the napkin is back wadded in Carrie's hand.
When Doug grabs multiple condiments from the kitchen counter to enhance his tasteless diet dinner, one of them falls off of the counter toward the camera. However, there's supposed to be a wall there (that the audience can see through).
Just before going to the card game they show a shot of the outside of the house. The front door of the house has three narrow vertical windows of increasing size. But when the scene moves to the inside the front door has only one window at the top of the door.
When Doug and Carrie go ice skating, an All Year Figure Skating Club banner can be seen on the wall. All Year FSC is based solely out of Southern California.