If you have a story that checks out, fine! Go with it. Run with it. But don't go out and hire two document experts and ignore their warnings about airing fake docs. Don't put blinders on. Tell the whole story. Freedom of the press is great. But with freedom comes responsibility. And the last time I checked, forgery is a crime.
Also, CBS should have the decency to submit to a full internal and external investigation when their story starts springing serious leaks.
And if a source gave you FORGED documents, your source is now THE STORY and should be revealed.
I think you underestimate the difficulties. Did you read Newcomer on the fakes. He's a real first-rate expert. But he missed things, too. Even an expert can't be absolutely sure. And then there's the other side of it - competive pressures and the need to act, to make a decision. Don't forget this Administration took us to war DESPITE many misgivings expressed by many experts.
Forcing news organizations to give up their sources is a bad idea. Their business is exposing illegal and unwise activities by the powerful. They depend upon anonymous sources. Depriving them of this weapon is very much a two-edged sword. Something like trying to limit free speech.