Maybe, maybe ...
On the other hand, I still believe that this is not a 5D Mark III. Is remain the argument that the "focal plane mark" is on the right side and not the left side.
And why would 5D Mark III be tested with a 200-400 lens and a 600 lens (wildlife too)?! This suits better to a really fast focus camera like 7D or something new.
Wildlife photography was done well before autofocus, let alone "fast" autofocus was invented. The fact they are making pictures of birds does not disqualify this as being a 5D mk iii. Your implication that long lenses have no place on full frame cameras is perplexing.