 When writers Jane Beaumont Hall and Richard Doyon added the scene  about a backhoe getting stuck in the beach after digging itself into  a whole (and then the tide comes in), they wondered if it was too  silly to be realistic. They later found out that the same thing  actually happened in real life when treasure hunters had to have  their backhoe towed out of the wet sand after digging itself into a  hole. And it happened not just once, but twice.