Sometimes people hire an attorney just for advice because they think they're going to be attacked. In this case, however, I'd say Joe is beginning to wonder about the wisdom of his unfounded charges.
I suspect that Bush plans to play hardball on this one. That is, going ahead with a thorough investigation, as Bush ordered, was probably the last thing Wilson wanted.
This is because Joe knows that the "leak" will lead either to him or to a sympathizer in the CIA or State. And then Bush will be able to get rid of that person. (And said person will probably go to jail, or get very close to it!)