That's what's getting to me. NOBODY can make me believe that no one at CBS knew those documents were faked. It's part of THEIR JOB to know whether they're faked. Yet it took a few web sleuths a few minutes to BUST CBS and blow the whole thing wide open.
My thought/theory on this is that the networks probably use questionable 'evidence' on stories pretty frequently, as a normal way of doing business. Most targets of a hit story don't have the resources or voice to fight a network, and if they do, the network digs in its heels and starts digging more. I assume a lot of businesses or business owners might be somewhat apprehensive about a network with a vendetta against them, and would find it hard to PROVE anything is a forgery/fraud, etc.
A good object lesson is the ge/nbc vs GM pickup truck fabrications. NBC 'stood by their story' as well, even after GM sued GE, until apparently GM produced indisputable evidence. GE then settled for an undisclosed amount and had the NBC president apologize on the air, but the fact NBC was ready to go up against one of the biggest companies in the world with faked material tells me they don't think twice about doing it to a smaller entity.
They got careless. There was no reason for those memos not to have been faked on a typewriter from that period.