As someone who watched helplessly as a man walked to his demise into the tail rotor of a running helicopter, I can tell you that there is quite a bit of shock and confusion immediately after such an event until people get their act together. It may take a minute or two. Since it's usually a (severe) head injury type of accident, nobody really knows what to do. Makes you extremely paranoid about tail rotors and people from that point on. But I'll tell you what - after witnessing such a thing once, the second time (watching this Astar video) is no big deal. Very sad, though.