Stupidity: After the Slick devours Laverne, Randy jumps into the water and swims for shore with the Slick following. Even though Randy made it to shore, he stops and turns to confront the Slick, screaming that he beat it. When Randy turns around, the Slick immediately envelopes him. If Randy had just got up and started running instead of facing the Slick, he would have lived.
Revealing mistake: When the elder Indian (Native American) with the black hat steps out of the yellow car at the beginning, and says hi to the shop owner, then Hi to the wooden Indian chief. You can see the Indian chief move slightly, indicating it is not a wooden statue, but a real person under the getup. (00:04:52)