Revealing mistake: When Jim is at the first gas station trying to reach a phone, he walks outside and John crashes through the garage at the side, if you slow it down you can see that the door to the garage is made with cardboard or paper, or some other soft material. (00:21:20)
Continuity mistake: When Jim eats at Nash's workplace, in one shot there is no napkin, knife or fork in front of Jim's plate. Then when Nash walks away it cuts to another angle, and now there is a knife and fork on a napkin. (00:28:00)
Continuity mistake: When Jim stops for coffee in "Roy's Cafe," John sits opposite him, and if you watch closely in one of the shots, the plant behind Jim gets knocked over, yet a few shots later it's back upright standing in its container. (00:49:15)
Continuity mistake: When C. Thomas Howell is looking in the mirror, in the shots taken from above the mirror, it is not that dirty. Yet, when it cuts to a close up of the mirror, it is filthy.