Seriously? You sitting next to the guy are going to reach over him and start putting a tourniquet on while the nervous cop who has just shot the man is pointing a locked and cocked handgun at him?
What, do you think 4 more bullets fired into you and the guy already shot will help ?
Beats sitting there recording someone bleeding to death. I understand the concern about alarming the cop. However I would be demanding to administer first aid, (i.e. a tourniquet) instead of sitting there calmly narrating and filming his death.