While Knox (Tom Berenger) and Stantin (Sidney Poitier) are cooking out the night after Stantin saves Knox from falling into the gorge, Stantin mistakes the marmot Knox is cooking for rabbit and says that he has eaten rabbit in "lots of places" in the city. Knox quickly corrects him, and Stantin replies, "Marmot? What's a marmot?" Knox says, "A rodent." Stantin gets a queasy look and says, "A RODENT? You mean a rat?" Knox replies, "Kind of a big, hairy rat, yeah." Stantin then gets disgusted and says, "OH SH**!" However, a rabbit is a bigger, hairier member of the rodent family.
When the jeweler wraps the diamonds, the bag is open at both ends, and is essentially too pieces of cloth tied together (which is why some diamonds fall out when he picks it up). For the rest of the film, the bag is a proper bag made of a completely different material.
When Stanton has been rescued after the ferry incident he is on a boat being taken to shore. The boat has a registration number identifying it as not only registered in California, the XC suffix identifies it as belonging to a law enforcement agency in California.
The ferry is supposed to be over deep water, with several shots of something sinking to murky depths, but when a character is seen being rescued by an unassisted swimmer the lake floor can be seen behind him with surface light shining down.
The goof item below may give away important plot points.
After (Tom Berenger) and Stantin (Sidney Poitier) find the bodies of the hikers in the river, in the wide shot right after Knox looks up and screams "Sarah", a truck drives into the scene in the upper right corner of the frame, revealing that they are not in a spot deep in the wilderness they could only get to by three days of hiking.