I agree with you but only because I have a gut feel that you are right.
Your statement that Dan Rather would never consider Bill Burkett as an "unimpeachable source" is, however, dead wrong. People on the Left are quite capable of listening to the likes of Bill Burkett and accepting what he says as absolute gospel. Don't doubt it for a minute. You establish your credentials with Rather based on your beliefs, in this case your hatred for George Bush. That is all it takes to become an "unimpeachable source". It's a "he must be telling the truth because I believe everything that he says" kind of circular logic that is characteristic of Left-wing types like Rather.
Can't agree more.
Anyone who doesn't believe Rather is dumb or devious enough to use Bill Burkett as an "unimpeachable source" needs to read this story.
"The First Rathergate" at:
http://www.nationalreview.com/comment/morse200409150552.asp
I think his only criteria is:
1. Does it further the cause.
2. Will the ignorant peasants suck it up.