I think the question should be… why didn’t these people interfere? I think 20 years ago everyone would. We’ve created a society in which it pays to mind your own business. There is a social price to pay for speaking out, even in the most dire of circumstances. Everyone can absolve themselves of responsibility because any misstep is rounded upon by the mob. When faced with an unpredictable punishment for action or inaction, most people choose the latter. The filming was to cover themselves, they were doing the ‘right’ thing. Everything must be someone else’s problem.