If there were 4 people on-camera there were at least 40, if not more, off-camera. Remember somebody is shooting the video of the camera crew. There was an ambulance/medevac helo standing by I guarantee you. No production company would take a chance with a celeb of Ferrell's standing otherwise, whether you think he's funny or not. When actors talk about not being allowed to do certain stunts due to "insurance", they're telling the truth. The cost of something going wrong on a film or a television show is way too high to risk these days to let untrained actors do anything really dangerous.