Continuity mistake: When Larry and Richard listen to the recording of the phone conversation between Bernie and Paulie, there is a slight difference to when they had the conversation live. After Bernie told Paulie where his house is located, Paulie replied with "Uh huh" which is not heard on the recording. (00:29:05 - 01:04:45)
Audio problem: After Bernie falls off the back of the boat, he hits the channel markers as they go past, ringing the bells at the top. The boat passes the last one, but the ring of the bell is too early. It took a second or two after passing for a bell to be rung for the previous markers. However, for the last one, it rings just as soon as they pass it. There aren't any other rings after that.
Continuity mistake: After Larry and Richard put Bernie on the couch, his legs are uncrossed as Richard notices the stuff falling out of his pocket. But, when he says that Bernie is dead, Bernie's legs are crossed when Larry walks back over to the couch. If he's dead, that shouldn't happen, since the guys obviously didn't pose him like that.
Continuity mistake: When Larry and Richard arrive at Bernie's house and talk to the lifeguard out the front, there is only sand leading up to the house. Later when Richard leaves the party and runs onto the beach to see Gwen, and at the end when Bernie is being taken away by ambulance, there is now a wooden walkway leading down onto the sand.