Thank you. I am already very well aware of marital privilege laws though.
We honestly don't know the answer to that anyway. It could be because he stupidly loved her or he could have married her hoping she would open up and tell him more about what happened that night or he married her because he was afraid he would be charged with statutory rape.
But if he thought by marrying her he wouldn't have to testify then he would have never divorced her in the first place for I am sure by then he knew the marital privilege would not apply either before the marriage or after the divorce. If he wanted to keep her silent he would have stayed married to her. He didn't.
IMO