Hartley, in other words, because it doesn't fit in with the prosecution case about clean hands, it therefore must be a photographic anomally.
No not at all. As I said it's certainly interesting, if the marks were seen on the original or after scientific examination of the negatives then that would be worth something, but the low quality image blown up by Abs isn't basically due to it's origins.
I didn't suggest it's a photographic anomaly, it's simply a fact that in order to resize a digital image by changing the resolution, then a computer programme such as Photoshop or Paintshop-Pro uses a computer algorithm to split the pixels and fill in the blanks, on the full size image when viewed in Photoshop and zoomed in to see the individual pixels, there is no change in colour tone, the greyish brown marks are not there.
Try it yourself.
Hartley. I don't have photoshop or paintshop pro but I am interested in what your are stating, if I don't quite understand it. Sorry I'm not the sharpest tool in the box on this kind of thing. Can you re-phrase what you mean, about this, but in thick-person's terms? 
Okay, if you take any digital image, it's made up of lots of little squares of colour (like a chess board for example) if you zoom into the full size image all the little pixels are similar colour tones. If the image resolution is increased then the number of pixels are increased, in order to do this the computer programme needs to split the pixels and scale them, in order to keep the sharpness of the image it runs a routine to best guess what colour the newly created pixels should be, there is always a certain amount of distortion. In addition, if routines are run to lighten, darken, sharpen or soften an image (or one stop photo fix for example) then some details are lost and distortion is added. An enlarged digital image will never be as accurate as it's original.
In the original the grey/brown smudges are not present.