Find somebody who has some experience looking at digitally altered photos--photoshopping is often detectable. This is what did in that scientist who faked his cell research photographs; by changing the settings on the digital images, it became obvious that he had pasted stuff on, touched up, and enhanced. (I used to be in a hobby that used digital photographs a lot and routinely checked for altering of digital images, which was grounds for automatic disqualification in contests. These people were not photoshop professionals. If they could find it, you probably can, too).
However, if the damage was "added" later and the photograph itself is untouched, obviously this won't help. Good luck.