Well, sort of. It would be possible to extract the image data from a photoshopped file and put it together with headers from a camera file. I would think anyone technically sophisticated enough to do that would have been technically sophisticated enough to use photoshop with pictures of real army guys, but in general image headers constitute proof of very little.
Damn,,that was a sexy post. I feel reallly really peculiar but I get the same feeliing when my electrician comes. Must be related to not knowing anything about electricity or computers.
Impossible, unless you knew what you were doing to "hack" the headers.