As far as the provenance of the documents goes, I think this case may be resolvable by coming at it from two ends. Since the forgery was obviously done by someone purporting to be an expert who really wasn't, that person is probably not as professional as he should be for something so high profile. That means people can probably get him to talk and come forward. I think that's how the case will be cracked.
I think DeepWord will appear from within CBS to take Rather down. He has lots of enemies.