Yes exactly.
The fax did not identify Wilson. At some time after the fax was received Libby learned that it was Wilson being discussed in the fax. There is no evidence that it was already known to be Wilson by Libby, and the content of the fax would suggest that Libby did know at the time that it was Wilson, much less know about Plame's role.
It was only shortly after this that Woodward showed up with notes to ask Libby about Wilson's wife. It was probably then that Libby learned about the Wilson/Plame/CIA nexus, and possibly then that Wilson's name was written on the fax.
The real question is: where did Woodward learn about Plame?
This is where the story is.
"The real question is: where did Woodward learn about Plame?
This is where the story is."
From a *former* top level Bush official.
I would guess Powell. Though I guess it might have been Tenet.
In either case it dramatically undercuts the claim that the outing was payback for Wilson's (mendacious) editorial.