I don't know about Bill O'Reilly's background but Clark (4-Star General retired) graduated at the top of his class at West Point and was a Rhodes Scholar. He also had an impressive military career that spanned 40 years and is one of the most highly decorated miltary men in the country. He has been awarded the Silver Star, five Defense Distinguished Service Medals, four Legion of Merit Awards, two Army Distinguished Service Medals, two Bronze Star Medals and the Purple Heart.
All of which made it even more astonishing that he let the Malmedy remarks pass by without a correction.