For years the man has been gnawing his way to an early grave and even his serious heart condition was never a deterrent. Why would anyone bother to engage snipers and high power rifles when a sumptuous buffet would suffice?
It's somehow connected with the items that men dressed in police uniforms took away from the car. How did they know what to look for and what to take away? It was not a random act, but one well planned and executed.
Man, you and the Kid are reading too much of Sherlock Holmes! As I said before , why would anyone go to such length to plan and execute an elaborate hit in broad day light, in an area of open fields, on a moving target in a bullet proof armor plated vehicle, when there was ham & bacon in abundance at the buffet table? The vices of Henry Greene makes him such an easy target for assassination by far less sophisticated method than the one you and the Kid are advancing. The man had a weakness for women and food that would make him a sitting duck for the dumbest f^%*!