There was a short interview with the photographer this morning on the national news. He indicated that he was not strong enough to pull the man back up onto the platform. Perhaps, but you would think most people would try.
However, events like this may unfold very quickly, and for many people there is a lag time for the brain to process the information before any action can be taken. It is much easier to analyze an event afterwards that you did not witness first hand and say "I would have done such and such."