Up to the guy to deal with his problems?? Isn’t he doing so by stating that he is not the father and trying to enforce his rights and innocence in court?
The baby is not his problem. The courts are.
No, he’s the father to his own problems here. He married the baby-mommy. He’s gotta’ get himself unmarried and have issues of support settled within the context of a divorce ~ not just the context of a marriage.