Fats' body is suddenly reversed between camera angles while sitting on Corky's knee when they are in the club dressing room.
Ben Greene comments that the IQ of his three "genius lawyers" must "total up to 100." Given the average IQ of a person is 100, this actually doesn't say much for three lawyers. However, Ben is obviously not being sincere in saying any of the lawyers are "genius", and his statement is not him making a mistake but a pretty vicious insult about how he thinks they're idiots.
Greene can be seen blinking and his chest rising and falling when Duke is giving him CPR, even though Duke determines he is dead.
When Duke and Corky are fishing, Duke casts his rod and there is a buzzing sound, as if the spool is unwinding against a clicker. The reel is a spinning reel, which the line comes off free spool during a cast. There would be no clicking sound.
Members of the crew are reflected in the cabin window when Corky gets his jacket before going out in the boat with Duke.
The high school yearbook is emblazoned with NHS. As it is stated that they grew up near Grossingers, at least the yearbook should be LHS as Grossingers is in Liberty, NY. There are no high schools beginning with N.