If it was a known "event" at the time (i.e., all the photojournalists knew the procession was coming and planted themselves in an "ideal" location), and you imagine a TMZ-like throng of photographers with their flashes firing from all angles, the inconsistency of the lighting might make sense.

Note: I don't have an opinion of whether the image is fake or real, but I am not sure the OP's analysis considers all possible lighting situations.