Game over, man...game over!
The only expert cited by CBS in this case, Marcel Matley, wrote in the September 27, 2002 issue of the journal, "The Practical Litigator":
In fact, modern copiers and computer printers are so good that they permit easy fabrication of quality forgeries. From a copy, the document examiner cannot authenticate the unseen original but may well be able to determine that the unseen original is false. Further, a definite finding of authenticity for a signature is not possible from a photocopy, while a definite finding of falsity is possible.
Attempting to authenticate a signature from a photocopy is exactly what Matley did for CBS.