Looks like Mark and others were holding out for some immunity on the issue before they testified before congress a few years ago that led to the "I don't want to talk about the past" statements. A lot of it seems to be protection for his family and other players who were involved. McGwire apparently told Congress behind closed doors that he did use steroids but he didn't want to 'throw anyone under the bus' in front of Congress, and wanted to stay away from prosecution.
