The only plausible motive I can think of for why Rather et al would protect the source of these documents -- once they admit the truth -- is that the source of these docs is even more embarassing than the fraudulent nature of the documents themselves. If it's Chris Lehane or Ben Barnes or someone else tied to the Kerry campaign, CBS News will have actively aided and abetted a partisan smear. And they can't afford to admit that.

Emily Will, a veteran document examiner from North Carolina, told ABC News she saw problems right away with the one document CBS hired her to check the weekend before the broadcast.

"I found five significant differences in the questioned handwriting, and I found problems with the printing itself as to whether it could have been produced by a typewriter," she said.

Will says she sent the CBS producer an e-mail message about her concerns and strongly urged the network the night before the broadcast not to use the documents.

"I told them that all the questions I was asking them on Tuesday night, they were going to be asked by hundreds of other document examiners on Thursday if they ran that story," Will said.

But the documents became a key part of the 60 Minutes II broadcast questioning President Bush's National Guard service in 1972. CBS made no mention that any expert disputed the authenticity.

"I did not feel that they wanted to investigate it very deeply," Will told ABC News.

A second document examiner hired by CBS News, Linda James of Plano, Texas, also told ABC News she had concerns about the documents and could not authenticate them. She said she expressed her concerns to CBS before the 60 Minutes II broadcast.

"I did not authenticate anything and I don't want it to be misunderstood that I did," James said. "And that's why I have come forth to talk about it because I don't want anybody to think I did authenticate these documents."