pic 4 looks a bit odd.... where is the rotor wash?
Photoshop, unless the Oryx is flying over ice.
If it is ice, then the colour is strange - there must be an interesting story there either way.
I think that the forward velocity of the chopper is greater that the down draft velocity of the rotors, thus the wake is just out of frame.
I'd have to go with xTzar's explanation. If that is a photoshop, it's just too good - the light, reflections, shadows and details are just too spot on.
He'd have to have been moving rather fast though - even given shortening of depth of field with a zoom lens, he's rather close to the water!
Good picture, great flying.