Reid should be sued for slander. Unfortunately I think that the Senate is immune from slander for stuff they say on the floor of the Senate, which is too bad. In this case, it could be easily proven that Reid had intentionally lied to impugn Saad's character with malice aforethought. This would have been a slam-dunk for Saad to win a slander lawsuit if it had not been said on the floor of the Senate.
Makes one wish that dueling was legal.