This defense is enough. Dan Rather isn't going anywhere and CBS is not going to admit that the memos are forged. Not today, not tomorrow, and probably not the day after tomorrow, either. The CBS stonewall is permanent.
Why? Several reasons
(1) IF they admit the docs are forged THEN they have to answer two other questions which make matters much, much worse for them. (Question 1: Why didn't you realize these were obvious fakes? Question 2: Where'd you get them?) The answers to those questions are likely to be much more injurious to CBS News than the current perception--that the network simply got snookered.
(2) CBS can't afford to lose their franchise anchor six weeks before a presidential election. If CBS were to admit that the memos were forged, it would be difficult not to require Rather to fall on his sword. CBS needs Rather to cover the election for them; without his presence, their ratings would likely crumble during the crucial election period.
(3) The Law of Diminishing Returns. With every day that passes, CBS spends more and more ethical capital in the defense of the documents. At the same time, the reward for coming clean becomes smaller and smaller. At some point, their defense will have made them look so bad, and a capitulation will look so pathetic, that it would actually hurt them to admit the truth. Some people think that break point is in the near future. I think it came around 5:00 p.m. on Tuesday, September 14.
(4) They now have a working defense. The September 14 Dallas Morning News story about Marian Carr Knox was a tactical defeat for CBS, but a strategic victory. Her testimony allows them to sidestep the issue of forgery. The CBS line in the sand is now: There are experts on both sides. You can't prove they're fake. Killian's secretary says they're true enough.
No, Dan Rather is entrenched and, as an analytical matter, it's difficult to see why CBS would crack now.
Update 11: 30 p.m.: Of course I could be totally wrong: There are two things which could break CBS. (1) Internal revolt. If someone at CBS gets fed up with the situation, they could come out and force Rather and Heyward's hands. (2) Someone discovers and outs the forger.
6 hours ago