... should be made to pay support after realizing he was not the biological father.

Actually, paraphrasing loosely, the original question was whether he ...could be made to pay support after realizing he was not the biological father.

But moralizing is a lot more interesting, and quite a lot easier than discussing legalities.

Having known a couple or six of people involved in somewhat similar situations in the US, my impression is that it's "conventional opinion" that the law is unresponsive. The instances I've seen have been "settled" by the parties involved in spite of legalities, rather than by seeking out courts and asking them to do it all.

While the resolutions in those cases likely were a lot different than a judge would have ruled "had to be done," it's sort of to be expected that life's like that, and usually it will go on. In the cases I've observed, the children have done well enough, both mothers and fathers survived, the good guys remained good, and the assholes were still assholes; but that's how it is sometimes.

John