Mr. Rebbetzin: Completely incomparable. Here we’re talking about people whose families we know with certainty discarded the Torah and Judaism generations ago. There he didn’t discard the Torah and Judaism.
Furthermore, and this is a point contemporary Gedolei Poskim have made, traditionally throughout the vast majority of history few gentiles wanted to identify as Jewish. Jews were persecuted, prosecuted, expelled from countries, put in ghettos, pograms, Inquisition, Tach V’Tat, genocide, blood libels and holocausts. Thus if despite all that someone identified as Jewish, and he and his ancestors (per his testimony) practiced Torah Judaism, it was believable.
Today, the Poskim said, when there’s benefits to being recognized as Jewish rather than severe costs, self-identifying alone is wholly insufficient; especially considering that we know that we’re now dealing with almost 200 years of false conversions and so-called paternal descent.