You're right, it wasn't him, but since she more than likely wasn't undercover, can you explain why whoever revealed her role in recommending her husband broke any law?
I don't think that's a point. If the perception is that what he did was illegal or even falls into a grey area (not to say it is even Rove) then he becomes a liability.
The fact is he will be tried and convicted in the MSM who will howl if some charges (however small) are not brought. Guilt or innocence have nothing to do with it.