Surely as a Protestant, you MUST be taking things out of context or making it if it impugns Rome in the least, or this is not "official teaching," yet they quite regularly post articles that like this, are by some RC churchman, and often their own apologist do not even bother to seek the Nihil Obstat + Imprimatur. And this
book states that " more than three decades have passed since the historic first edition of EXTERNALS OF THE CATHOLIC CHURCH appeared. Ever since then it has been on all Catholic basic book lists.." Apparently such is only a matter of concern and its veracity impugned when invoked by a Protestant exposing Rome.