By the way, this doesn't exactly seem to be true, if I read that article's summation of Pope Paul right. He said that people who were forced to convert could not be regarded as Christians.
Whether that was private opinion of his, or whether that was reflected in bulls/legislation of the time I don't know--I'm not a historian of the period. But it does seem at least that there was no automatic assumption that those forcibly baptized were full Christians.
It may have been Pope Paul's opinion. But it was NOT the opinion of the Inquisition in Spain or Portugal. Indeed, if anything, the POINT of the Inquisition was to ferret out, try, and frequently torture insincere converts. Not surprisingly, that population consisted overwhelmingly of Jews who had been forcibly converted, or who had been raised by parents who were forcibly converted.