After getting bashed for ten straight minutes, Schieffer ended the interview. Lew Rockwell reports that "Schieffer promised Ron 2o minutes."
Also, for you deep conspiracy theorists, consider the possibility that a little technological disruption might have been planned for Dr. Paul. Lew writes:
...there was a loud buzzing from Ron's earpiece during the entire interview. Deliberate? Who knows, but the flaw had been pointed out again and again 15 minutes before airtime.