Whats the rules for charges brought by special prosecutors? Can they prosecute for any crime they may find regardless of correlation to the investigation? Or are they subject to constraints around the investigation itself? Depending on how some of the details of his financial misdeeds occurred, its possible that subpoenas were issued under the guidance of looking for certain things when in fact they found completely different evidence. Under that scenario, its possible that he could have a case, but its the kind of technicality that even if he won, he would still lose in the court of public opinion (a narrative the media would be happy to push).