Mobertermy,
Reading back through this thread, I think you're approaching this whole problem in reverse: you've decided that the photos have been manipulated, and went looking for corroborating evidence in the photos.
What several of the posters have stated is that it should be the other way around - if the photos are, as you say, evidence (or data) - use them and align them to a sight line plot to identify the deviations or anomalies. That then gives you the truth of the photos, within a significant margin of error.
Having said that, I can tell you as a photographer that I can make any photo show what I want to show you, and you wouldn't have a hope in hell of picking whether I've added, removed, amended or distorted anything. I don't even have to use photoshop - with a wide zoom and telephoto zoom lens and some judicious cropping I can dramatically alter sight lines, fields of view, and perspective.
If you were going to ask me to validate the photos I'd want to see the camera and the settings used at the time. What format sensor, what lens focal length, what aperture. I'd want the original images - raw files on the card. If it was jpeg I'd already be worried, but if I could trace the providence I'd me more happy.
Regards,
KE