He is already laying the groundwork for defending the leaker because he expects the leaker to get caught.
And, as a bonus, this idea of "intent" is entirely consistant with the lib mindset.
If the motivation was to screw Bush, well, what could be more selfless and admirable?
What's wrong with thinking that it could be a case of old fashioned espionage, conducted by a foreign nation, or possibly even the NYT?