Richard is shown wearing a wedding ring during the movie. He isn't married as he is trying to date Gwen. However, he may have once been married but then his wife died or he got divorced, and he kept the ring.
When Larry is commenting on Bernie's drug habit, with his back to the camera, he says, "I watch 20/20, I know the statistics." When he turns his face to the side, he is still speaking, but his lips aren't moving.
Bernie is dropped over the side of the deck, next to the house and is later swept out by the tide. Later shots show a dune between the ocean and the house, revealing that the tide does not come up that high.
When Richard confronts Larry about throwing Bernie's body over the deck he is barefoot. When he subsequently goes to call the cops, he is wearing shoes. But then when he runs outside onto the deck and then the beach with Larry to retrieve Bernie, he is barefoot again. Once he and Larry bring him back inside of the house to vacuum sand off of him, his shoes are on once again.
When Larry, Richard, and Bernie are in Bernie's office discussing the missing money, Bernie walks over to the bar, drops the paperwork on the counter, and opens the left door completely. In the next shot, the left door is closed.
When Larry and Richard are getting lunch at a food stand, they see Bernie entering a building with the entrance awning reading East 70th Street. When Larry and Richard begin walking down the street, a sign behind them reads 52nd Street. Larry and Richard must have had extremely powerful vision if they were able to see Bernie from 18 blocks away.