I've just compared this image with several other images of the 5D mkII - and that's what it is - a mkII...
Of more interest is the fisheye zoom!
I think the OP is right - the angle on the top-front of the pentaprism housing is not rounded enough for it to be a 5DII. Also, though it's tough to tell with the small image, the knurling on the mode dial looks like the vertical lines of the 5D, vs. the little squares of the 5DII.
Why, exactly, is the fisheye zoom interesting?
If it were a 5D classic, then what is he looking at? Live View on a Mark II, presumably?
The review image on the LCD. Before Live View, to shoot in a situation where you couldn't look through the VF (and didn't have the Angle Finder C or equivalent), you'd aim, shoot, review, adjust, shoot, review, etc. - tedious, but effective.