mullacc, the whole deal with the coin toss is that that crap-fuck Chigurh (oops I am swearing again, my sorrys) is a sadist. He'd probably kill them anyway...
Carla Jean: ...You got no cause to hurt me.
Chigurh: No. But I gave my word.
Carla Jean: You gave your word?
Chigurh: To your husband.
Carla Jean: That don't make sense. You gave your word to my husband to kill me?
Chigurh: Your husband had the opportunity to remove you from harm's way. Instead, he used you to try to save himself.