I think the best thing would be for Michael to be released from his marriage and any financial obligations he has by being married. Once you commit adultery, you have broken your marriage vows --- he shouldn't be "unmarried" in one way -- having a new family going with a live in lover, but still "married" as far as having complete authority over his wife's life.
He may or may-not have remembered something Terri said many years ago, maybe he just thinks he heard her say something ---- memories 14-15 years later aren't always very reliable. She never put anything in writing or apparently told her family or loved ones --- his memory shouldn't be enough to condemn her to death.