This is where it gets kind of fuzzy. Burkett claims that CBS came to them and bugged them about it. We probably don't know who made the initial contact. I am sure Burkett let someone know that he got hold of documents given that he has a big mouth and penchant for posting stuff on the web. Mary Mapes probably heard about either from him or via someone else.
I think you are overdoing with all this conspiracy stuff. The most simplest explanation is that Burkett (and/or his pals) forged these documents. Then Burkett passed them off to CBS. And Burkett told Lockhart to use the story to destroy Bush.
Okay, I'll remove my tin foil hat................LOL
Since the memos do have language that is more like 'Army' talk that 'Air Force' jargon....what you say about Burkett makes sense.