That night we stayed at Natural Mystic Lodge on the Zambezi River, where we met the five other members of our group plus our ace guide for the next week, Thuto.  He explained some safari etiquette:  If we were out of our vehicle and encountered something big and hairy, "Do not run, do not scream, do not shout.  If there's any of that to be done, I'll do it."  Then we signed release forms, absolving everybody else in the world of any responsibility if we were eaten, etc.  Asked if he had ever lost a customer, he said, "Not yet."