MacGyver says of the dead reverend "Six, two, and even somebody killed him." This started as a horse racing phrase. 6 to 1 a horse wins, 2 to 1 he places, even money he shows. Those are decent but not great odds. Eventually the phrase came to mean something is very likely.
Richard Dean Anderson (MacGyver) would later appear in an episode of Stargate SG-1 (1997) with the same title: The Enemy Within (1997).