You've hit on it. The Kerry people did not anticipate that the actual documents would be put up on a website, and, apparently, CBS thought the story was so "hot" that the charges would be the issue, not the origins or authenticity.
And, if McAuliffe blames this on Rove, he makes the entire DNC look like the biggest bunch of dummies in the universe.
Who would entrust the presidency to people that braindead?
The key to all this is the forger. He needs to be found. He misrepresented himself to the perpetrators as a professional but he wasn't and that fact alone means he can probably be located and made to talk. I think this is the weakest link in the chain of provenance.
A little over a month ago, my brother & I were discussing Bin Laden and 9/11. I said that the 9/11 operation was the dumbest thing they could have done & couldn't understand why they did it. He said that they believed that they would get away with it. Certainly history did not tell them anything different. Looks like the media has a similar situation here. They do not expect to be called on their lying.