- Tommy's door reads "Tommy Callahan III", but he is introduced to fellow workers at the end of the film as "Tommy Callahan Jr."
- When Tommy bends the car door back into position at the gas station, it is visibly dented and crumpled along the edge. Immediately after, Richard goes to open the door, it falls to the ground, and is in pristine condition.
- Tommy's life jacket occasionally has a tag on it.
- No Cadillac has moving seatbelts similar to those indicated.
- In the airplane restroom, the door was not opposite the toilet, yet when Tommy pulls his tie out of the commode and falls backward, he goes through the door and into the aisle.
- At the wedding reception, we view some of the scene through Richard's camcorder. However, most of the cuts between shots could only have been made with multiple cameras.
- Tommy reaches for the life preserver with his left hand. In the next shot, he is grabbing it with his right hand.
- While on the streets of Chicago, as he's about to pitch brake pads, it's revealed that Tommy has a clip-on tie. Once inside the building, it's obviously a tie-on type.
- While in the airplane, when Richard goes into the bathroom, it is clearly a double. Then, visible through the crack, the double can be seen to go left as Richard comes back out the door.
- During the "bees" attack, Richard's head hits the plastic car window, but makes a noise like it hits a glass window.
- The toy hand that Tommy uses to flick off Richard periodically changes places.
- When Ray starts the hanging engine, the fan blows Richard's toupee off of his head. The fan on a car engine sucks air toward it rather than blow air away from it as indicated.
- When Tommy and Richard are on their cross-country trek, Tommy slams into the glass wall in an office. On the glass wall, it says "Greater Detroit Auto Parts". Later in the film, after they have been to many other places across the Midwest, they are seen driving directly into Detroit.
- In the last scene, Tommy's boat is in shallow water. Yet when the wind picks up, his boat is farther out in the lake.
- While waiting to depart, we see a shot of Tommy and Richard's plane waiting at the gate, and it's clearly a two-deck 747. Later, there is an exterior shot of the plane in flight and it's another type of plane, with only a single deck.
- When Tommy struggle to change clothes in the airplane bathroom, he breaks the toilet seat off twice.
- When Richard is telling Tommy about his 1967 Plymouth GTX he says "I dropped in a 440 Magnum with a six-pack" (3x2v carburetors). But when the hood comes open it has a 440 Magnum with 1x4v carburetor which is the original engine on this vehicle.
- The distance between Sandusky, Ohio, and Cuyahoga Falls, Ohio, is 65 miles. Why would Michelle fly home to her parents, when it's only a little over an hour's drive from Sandusky?
- In the scene where Tommy, his father, and the executives are in the brake pad division and Tommy is doing "Kung-Fu" with the moving hooks, his father catches him and tells him to come on. As soon as Tommy takes a step toward his father, the hooks stop moving, but clearly no one turned them off.
- When Tommy runs into the glass door after a successful sale, he leaves his makeup imprint on the glass.
- When Tommy and Richard come back from the airport, as they pass through town you can clearly see a Toronto Dominion sign (Green with big white TD written on it) on the corner of the street, just as they turn right.