Revealing mistake: One of the times that Sam comes over to visit Mr. Brady, he comes in through the back sliding "glass" door. There is no glass in the door. You can tell this because when Sam closes the door, to do so, he puts his hand through the areas where glass would be.
Revealing mistake: When Mike's boss, his wife and two other guests arrive at the house for a night of pool, the four guests are greeted at the front door, enter the brick entry foyer, and descend the steps into the living room. As the camera pans to capture the guests entering the living room, the obviously unfinished and unbricked end of the entry platform can be seen in the shot.