He created a nemesis by dividing a family.
Sam went undercover trying to bring down Al-Qaeda affiliated Tahir Khaled. Tahir's sister, Jada, fell in love with Sam and became a useful source of information. He ultimately told her the truth and convinced her to move to the U.S. and testify against her own brother. While Sam may have had a successful mission and has stayed in touch with Jada, he also created a nemesis who would come back to haunt him.