Revealing mistake: When Bob has difficulty with his seat belt at the start of the road trip, the side-view mirrors have a translucent finish, just as in other shots throughout the film; however, the mirrors' surfaces are normal in the rest of the shots. Deliberately done to obscure the reflection of the crew. (00:13:20)Super Grover
Revealing mistake: After the RV rolls over Bob, in the overhead shot as he lies on the ground, there are two tire tracks - one to Bob's left and another to his right. Problem is that the RV has four rear tires, which actually should have left the imprint of four tire tracks. (01:12:40)Super Grover
Revealing mistake: When Bob is on the bus' roof there are interior shots of the bus and all its right side (viewer's left) sliding metal framed windows are visible and intact. After Travis stops short, in the following exterior shots four of the double sliding windows have been deliberately removed from their tracks, so the camera's view of the kids is unobstructed. (01:23:10)Super Grover
Revealing mistake: When Bob hangs upside down on the Gornicke windshield, in the shot facing the bus as he begins to fall, we can see the driver's and front passenger's seats and Travis, his wife, and Jamie are all gone. Of course they are back in the following shot. (Only visible on fullscreen DVD.) (01:23:15)Super Grover
Revealing mistake: When Bob throws pitches to Carl while he barbecues, the close-up of the grill shows Bob's arm holding the tongs as he fiddles with the food. Problem is, it is not Robin William's notoriously hairy arm and hand in the close-up. Things on the grill differ between shots as well. (01:01:10)Super Grover
Revealing mistake: The Munro's RV has a large pop-out (slide-out) on its left side, behind the driver. When the pop-out is closed one side wall should be directly behind the driver's seat, but that wall is gone - it has been deliberately removed. As a side note, when the Munros rush to leave before Mary Jo Gornicke reaches them, that wall (with a small window) is seen in the exterior shot, as it slides in. (00:19:15 - 00:39:30)Super Grover
Revealing mistake: When Bob is riding the pushbike down the steep hill to get to his family and the Gornickes at the bottom, in some shots you can blatantly tell that a stunt double that looks nothing like Robin Williams is riding the bike. The stuntman is also visible later when Bob is on the roof of the Gornickes' bus.