It remains to be seen whether or not they will get the documents through the courts. But your statements that "The president invoking executive privilege does mean he is involved" and "The president cannot invoke executive privilege on something his office is not involved in" show that you don't know the facts about executive privilege. By your logic, President George W. Bush was involved in the death of Pat Tillman. And speaking of Dubya, he himself invoked executive privilege in a situation very similar to the one with Holder. So are you telling me HE had something to cover up, and might have been impeached had it come out?
http://articles.latimes.com/2008/jun/21/nation/na-epa21