I don't buy his argument about inconsistent left-right lighting in the Gaza photo.
Assuming the sun is really top-right, it is actually expected that people's faces are illuminated from the left, given the setup: the people are between two walls, the left one being illuminated, the right one in shadow. The light you see on their faces is reflected from the left wall.
The light isn't from sunlight reflecting off the wall. It's too... directional? It's also too bright, and the colour might be too warm. I'm not entirely sure how to explain it, but I've done enough photography to recognise that as an artificial light source.
But using an off-camera flash is not the same as Photoshopping three photos into one, and the OP not even mentioning a flash as a possibly explanation for the "inconsistent" lighting leaves me with significant doubts.
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.
Assuming the sun is really top-right, it is actually expected that people's faces are illuminated from the left, given the setup: the people are between two walls, the left one being illuminated, the right one in shadow. The light you see on their faces is reflected from the left wall.