The guy Trump retruthed is Robert J O'neill the Seal Team Six guy who claimed to kill Osama Bin Laden.
Robert J. O'Neill (born 10 April 1976) is a former United States Navy SEAL (1996–2012), TV news contributor, and author. After participating in May 2011's Operation Neptune Spear with SEAL Team Six, O'Neill was the subject of controversy for claiming to be the sole individual to kill Osama bin Laden.
https://en.wikipedia.org/wiki/Robert_J._O%27Neill