Who "this guy" is, partly answered by Wikipedia:
Joseph C. Wilson IV (born November 6, 1949) was a United States career foreign service officer and diplomat between 1976 and 1998.
Wilson served as U.S. ambassador to Gabon and São Tomé and Príncipe under President George H. W. Bush and helped direct Africa policy for the National Security Council under President Bill Clinton.
He was hailed as "truly inspiring" and "courageous" by George H. W. Bush after sheltering more than one hundred Americans at the US embassy in Baghdad, and mocking Saddam Hussein's threats to execute anyone who refused to hand over foreigners. As a result, in 1990, he also became the last American diplomat to meet with Saddam Hussein.http://en.wikipedia.org/wiki/Joseph_C._Wilson