Continuity mistake: When they are playing hockey, and they win with 1-0 you can see the team celebrate. In the background you can see a scoreboard that says 4-1.
Revealing mistake: When Dennis gets frustrated with the contraceptive foam and throws it aside, it is obvious that a machine is at the bottom of the screen to make all the foam squirt out, since it sprays from a different location than from where the cannister was thrown.
Continuity mistake: When Steve and Doug first go to the Roxbury, the bouncer tells them that they can't go in. Then, Richard pulls up in his yellow sports car, and goes into the club, leaving Steve and Doug behind. As Steve and Doug walk to the back of the line, you can see Richard's car parked about 20 feet away from the entrance to the club. Nobody moved it. How did it get there? (00:06:15 - 00:06:40)
Revealing mistake: When Angus is chasing his Mum, Sally, and Dorian in the helicopter you can see through the windsheild of the helicopter that the road is blocked off with orange cones and police cones when earlier there was traffic on the road.
Factual error: During the Mars-flight, the way the spacecraft uses the rocket thrusters is unrealistic. For example when they are nearing Mars, they should be using the rockets against their movement, to slow down the speed. But in the movie they are using the rockets towards Mars.
Continuity mistake: Near the beginning of the film, "Elvis" is driving Byron's car, and has a diamond horseshoe ring on. They show a close up of it as he's driving, and in a subsequent scene, the ring has been turned around.
Continuity mistake: When the two girls are on the floor, just as the phone rings, Tomoko (the girl in green) has her right hand on Masami's (girl in red) shoulder. Cut to a different angle but now, Tomoko has her hand on Masami's arm instead of her shoulder.
Visible crew/equipment: When Steve rejects Brad Conway's new book and Brad says "what is it exactly?" there is a boom mic visible. (00:09:50)
Revealing mistake: At the fund raiser for the aquarium, a journalist interviews Max with a tape recorder but you can see that it is not running because the wheels inside are still. (00:32:05)
Revealing mistake: At the beginning, the dead policeman can be seen rolling himself with his arms. (00:06:45)
Continuity mistake: When Tony kills the first fat guy, the fat guy falls back in his chair. Yet after Tony kills the other fat guy the first fat guy is back upright in his chair.
Continuity mistake: In the locker room scene, Remer and Joe are both naked. When Remer goes to pull Squeak out the drawer, you see him put a robe on, but you also see him wearing underwear. It wouldn't be possible to put on underwear in about 1/2 a second.
Continuity mistake: In the scene on the Strip where Gonzo is vomiting out of the car and yelling abuse at the couple in the adjacent car, he vomits on the other car's window. After this, no vomit is visible on the window in shots from inside the other car. When shot from outside, the vomit is still there.
Continuity mistake: Toward the beginning when Philip Seymour Hoffman gets on the elevator with Lara Flynn Boyle, his tie is twisted all around but when he gets off, the tie has been fixed. He couldn't have fixed it because he was carrying two bags of groceries.
Continuity mistake: When Garrett is jumping on the bobbing things, we look down on him from above. He has one more thing to jump on before he reaches the other side. Then we see him from a different perspective and he has to jump 5 more.
Continuity mistake: In the love scene between Mario Van Peebles and Rae Dawn Chong, her breast is uncovered, then covered, and then uncovered again.
Continuity mistake: In a bar scene when Doplh Lundgren is doing shots, he does one, the camera pulls out and he finishes the already completed shot.
Factual error: In the opening narrative about the first person to call out "America", as the ship passes the Statue of Liberty, it's traveling in the wrong direction - with the Statue entering the screen from the viewer's left and moving toward the right; a direction that would have taken the ship from Manhattan to Staten Island (or through the Straits into the Atlantic).
Revealing mistake: After Hank shoots Lou's wife in the kitchen, the camera shows Jacob walking into the house, then Lou's body on the floor with a puddle of blood around his head. If you watch closely, you can see Lou's left eye twitch.
Visible crew/equipment: A boom mic drops in when the hitwoman is asking where Riley is, after the shootout.