Also very important is the fact that one cannot claim “partial” privilege. Holder and the DOJ have already provided info about the February 4th, Ron Weich letter, for example. It is not legally permissible to now claim privilege on the remainder of that documentation. When part of it is out, the rest becomes fair game!!! One cannot testify and then claim 5th Amendment protection for the REST of what he was going to testify to!!!!
I think they are only claiming EP for that part of the documentation set that involves discussions with the White House, so a partial claim is possible if there have been no releases of such communications (which I think is the case).