When I was in NY recently, I tried to keep to myself and not look so much like a tourist. That was possible until I opened my mouth and asked things like " where is y'alls bathroom" If I had saw a homeless man laying on the sidewalk I would have not thought a lot about it UNLESS I saw the pool of blood. If I saw the blood, I would have told the police or someone in some type of authority. From the video, I didn't see any blood. It looked like another homeless man who was passed out.
NOW....on the other hand, if I had seen that same scene in Florence, Alabama, I would have definitely called for help.
It is kinda the same thought process you have when you see a car broken down on the side of the road. You wanna stop to help but now days you can never be sure that it would be safe to stop. Its sad but true.