Why did Barr and Mueller disagree on the special counsel's conclusions?

Jan Crawford, Jamal Simmons, Susan Page and Ramesh Ponnuru discuss Jan Crawford's interview with Attorney General William Barr and special counsel Robert Mueller's first public statement.Subscribe to the"Face the Nation" Channel HERE: http://bit.ly/1SUQc68Watch Full Episodes of "Face the Nation" HERE: http://cbsn.ws/20pbkSFFollow "Face the Nation" on Instagram HERE: http://bit.ly/23Xuhk4Like "Face the Nation" on Facebook HERE: http://on.fb.me/23Xmz9EFollow "Face the Nation" on Twitter HERE: http://bit.ly/1o3QDQoFollow "Face the Nation" on Google+ HERE: http://bit.ly/23XuaoGGet the latest news and best in original reporting from CBS News delivered to your inbox. Download CBS News mobile apps HERE: http://cbsn.ws/1Xb1WC8Get new episodes of shows you love across devices the next day, stream local news live, and watch full seasons of CBS fan favorites anytime, anywhere with CBS All Access.