In the book, Jack realizes that he may have confessed his accidentally killing a young couple to his wife after being forcibly stoned by a suspect. He comes home to an empty house and a letter that he assumes is her telling him she's leaving. Instead, it reveals that he did tell her, but she doesn't care, and has booked them a vacation in Hawaii where they can salvage their relationship.
"I know you're wondering, so I'll tell you. You talked in your sleep. I know the worst I can possibly know, and I don't care. We never have to discuss it. Captain Exley heard you and I don't think he cares either. (He's not as bad as you said he was.)"