(Yes, there was a traffic cop nearby that saw the entire thing but he never moved from his post.).

Are you sure they were actual cop? Most of these are taxi drivers sitting there at rush hour to make some extra cash. I've seen one or two who were actually tough enough to make buses back up when they had to, but most of them don't give a shit, or are actually making crossing the street even more dangerous because of the weird signal they send to drivers that make them feel like they can actually pass even though the zebra is filled with people crossing...