Continuity mistake: Bernie's facial expression changes from the smile on his face when he first get injected with drugs to a smirk throughout the movie, to no expresssion and back again.
Continuity mistake: Right before Richard discovers that Bernie is dead and Larry is talking about drugs becoming a career, "I watch the news. I read." There is a side/back view of Larry talking and neither his gestures or his mouth line up with what he is saying.
Continuity mistake: At the end of the movie, when the hitman comes to kill Bernie for one last time, Larry, Gwen, and Richard start running from the hitman and Gwen has her hat in her hand. They run over to the stereo and she drops it somewhere over by there. In later shots, however, you can see Gwen's hat lying right next to Bernie in front of the staircase.
Continuity mistake: When Richard and Gwen are kissing on the beach, a big wave pushes Bernie alongside them and you can see them getting wet from the wave but in the very next scene of them walking back to the house, they are dry.
Continuity mistake: In some scenes you can see Bernie breathing and blink his eyes when he is supposed to be dead.
Continuity mistake: When Larry and Richard are on the rooftop, the sky is seen as cloudy but when the camera cuts to a different angle, the sky is clear.
Audio problem: When Gwen is getting hit on by the drunk guy who says "nice outfit", the lines for both drunks have been poorly dubbed over and don't match their mouths.
Continuity mistake: When Larry and Richard are piling into the crowded elevator Monday morning with everyone, some of the people who get on are different from whom we see riding up. In particular we see the door close on a girl in brown with a green purse strap before she can get on, but she is seen riding in the elevator in the next shot.
Revealing mistake: When Larry and Richard are dragging the two bodies to the closet the first one lifts up his legs for Richard to put him in.
Continuity mistake: When Bernie's toupee falls off they show a few scenes of him in the house sitting there with a bald head. You can see that it's a bald cap. It makes Bernie's head at least 2 inches taller.
Continuity mistake: When Richard knocks out the gardener that's holding a knife, the knife lands right next to the gardener's hand (it's touching him). When Richard and Larry go to drag the gardener and the other guy, the knife is a lot farther away from the gardener's hand.
Continuity mistake: At the end of the movie, when the ambulance is shown backing up to Bernie's house, you can see a stretcher on the boardwalk that gets bumped and rolls down. This stretcher has Bernie on it, yet when it is bumped it is completely empty.
Continuity mistake: When Richard is using the phone to call the police, Larry's hand comes into the frame to hang up the phone. His sleeve is pulled up exposing his arm. In the next shot when they're in the entire frame, his sleeve is down.
Revealing mistake: When Larry and Richard put Bernie in the little red wagon, they take him to his golf cart and right before he falls out of the wagon, you see him putting his arm down so he can ease the fall.
Audio problem: When Larry and Richard are hiding behind the couch when they hear gun shots, you see the gun making its way around the corner of the couch and when you hear the next gun shot, you can see that the kid holding the gun is not even squeezing the trigger.
Continuity mistake: Just after the hit man kills Bernie he proceeds to disguise himself and pulls a folded, floppy beach hat out of his pocket. Yet when we see him getting on the boat in the next scene the same folded hat is now a perfectly round, structured hat with a brim.
Suggested correction: It's the same hat. That's the style, where it can be folded and open back up. Similar to a bucket hat.
Revealing mistake: When Richard and Larry tie Bernie's laces to their own so they can all run together, you can see that Bernie is running along with them because he is bending his legs at the knees at the same time they are and he's supposed to be dead.
Factual error: In the lunch scene outside their office, Larry and Richard are at the food stand and notice Bernie walking into a building. The entrance awning reads "East 70th Street". As they walk away the street sign behind them reads "52nd Street". Apparently they must have superhuman vision which allows them to see 18 blocks away.
Audio problem: When Richard falls off the boat, you hear him say "Why is this happening to me" but his lips never move.
Other mistake: In the opening scene in the office, when Andrew McCarthy says, "Let's go to the beach" and runs off, you can see that the other guy's PC, which he has been working on, has no power cable plugged in.