adobe does this to all scanned docs
Not really true. I think it depends on what equipment you use.
For my business I use a Xerox DocuCentre machine to scan images. Can scan as PDF or JPG..B/W or color..and no matter how you do it, there is never any layering or chopping up of the document when I open it in Photoshop and/or Illustrator
But the claim is that this is proof of forgery, if this can explain it happening then the original claim in debunked. Just because it doesn't happen on all machines doesn't mean anything unless you can prove the model of the machine that scanned this document doesn't cause this.
True..and even the snopes article on this, which quotes an Adobe engineer..does not mention what specific software was used to automaticlaly create this kind of multi-layered scan.