Everyone speaks so gently...

Packer & co have to be the gentlest-sounding miners/prospectors I've ever heard. Packer and Swan especially. They sounds like chilled-out high school guidance counsellors. This "unintentional" mannerism (according to the DVD commentary) is a real master-stroke. It provides the audience with yet another aspect of the movie (such as the beards, the actors, the costumes, sets, dialogue, etc) that it's just IMPOSSIBLE to take seriously.