The ex was thanking God that he divorced before she met the JWs.
I always thought that any divorce before baptism was considered a sin that didn't have to be dealt with. I think they deal with those who have KILLED people with more leniency-I remember reading some question of what if a guy confessed to murder before becoming a JW. I believe it just addressed the legal issues, not the moral ones, but basically the idea was that all was forgiven.