Revealing mistake: The paper towel holder is in front of Mr. Truett when he joins his son at the diner table. After Zach leaves, Mr. Truett moves the tray off the table and (off-screen) probably moves the paper towel holder to his left where Zach was sitting. However, some shots show the paper towel holder too close to Dave (which would be near the middle of the table) while other shots show it at the edge of the table (in front of Zach's empty chair). (00:20:35 - 00:21:40)
Revealing mistake: The tapered half of the baseball bat was leaning against the coffee table at about a 60° angle, but after Dave said, "The bat?" the camera showed it sticking straight up from (perpendicular to) the floor. Dave's lower body is then shown walking past the bat (which reaches to his waist) and stopping, at which point the bat fades into his leg until it is almost invisible. The next view of the bat shows it leaning against the coffee table again, but the coffee table is closer to the couch. (00:09:08)