Many times, we hear stories about how fathers wind up paying child support on children which are not genetically related to them. Ofttimes, this occurs from naivete, sometimes, by deliberate misrepresentation.
This Texas story is illustrative of such a case. A birth occurs, parentage was initially misrepresented by the birth mother, and a variance in proof was offered as to whether the support payee had any notice of the claims of paternity. According to the posted story, it appears that the putative father may have had notice, which he ignored or forgot about.
Under the law, regardless of DNA results which are declared years after a birth, a putative father has an affirmative duty to come forward as early as possible to contest parentage. If he fails to do so and an order is entered with any notice to him, he is likely to be held to support the child - up to and including large arrearages generated from the date to the initial order. The ramifications from these sorts of declarations are nothing short of calamitous for the fathers involved, and can affect everything from credit ratings to occupations to the ability to obtain passports and the ability to maintain paying ordinary household expenses.
It is important to seek competent legal counsel in order to assert your rights to legal due process prior to such an important legal declaration as early as possible.