While perusing the comments at sisu, I came across a blog - Fine? Why Fine? - I hadn't visited before and found this interesting tidbit there:
I cannot believe that a previous case in which Dan Rather stood by forged documents did not come up once--to my knowledge--during the whole Rathergate debacle. Must be read to be believed.
Now, at least I understand why CBS and Dan Rather stonewalled. Not being a lawyer, and not being a 'professional' journalist, I didn't quite understand what Times v. Sullivan could mean for Rather and CBS.