I see your points on this issue. In reading the opinions of the majority justices there seemed to be some very strong language that came down in support of the presumption of paternity -- even in the face of science. There was also some strongly worded commentary opposing interference by "strangers to the marriage". Almost seems like the justices wanted to make a social statement as much as anything else. I just wonder how many challenges to currently in-force child support rulings KY will get, if for no other reason than to determine exactly how "narrow" the set of circumstances is.
The Kentucky legislature has been touting their bills to "defend families" for years now, but they have yet to pass anything. There was a big argument for the legislature's consideration of the bill that went something like this: "what if a rapist got his victim pregnant and demanded paternal rights?"
BTW, in Kentucky you can challenge the paternity as well, but they consider the presumption of paternity to be the "strongest presumption known under the law".
AFAIK there is only one way to overcome the presumption -- you have to prove that the husband and wife didn't engage in "marital conduct" for 10 months prior to the birth of the child. The only accepted reasons, to date, are that the husband didn't have "access" to the wife (in jail, physically separated, dead), or that the husband could not perform marital acts (medical reasons).