If Mike Rossi does have "evidence" he will never post it online as it will have been doctored-up. He has had over a month to photoshop himself on to sections of the course, while removing other runners and cropping the frame to make it look like a unique photo. Any amateur photographer can easily do this with free software and it will look real if all you get is a quick glance. However, if Mike were to post such a picture online, this whole community would look at things like his shadow, the lighting on his clothing versus other competitors on that part of the course and zoom in really close to see if any pixels indicate that he pasted himself in the frame. He would likely be busted.
Same thing with his Nike GPS. It's extremely simple to alter the data and it looks as though he may have already altered it on one of his training runs. However, posting his doctored data online would open it up to scrutiny.
Obviously, it goes without saying that, if Mike really had this data, he would have posted it to his Facebook page, right at the start of the cheating allegations, when his acquaintances asked to see it. If he had made this data available immediately, it would have been worth something, now however, it can't prove his innocence but could very likely offer more proof of him being dishonest when we discover that he doctored it.