In the linked article, there are two points (link). One point is the quite silly and worthless ad hominem argument that Benedict XVI was (in his youth) a part of Hitler's Nazi Youth organization. There is no doubt that he was, he admits it himself. However, it was also compulsory. Furthermore, while someone might argue he ought to have sought martyrdom rather than be a part of the Nazi movement, nevertheless that was a long time before he became pope (see this more balanced article).
In short, standing alone, Ratzinger's participation in that particular evil organization (I mean the Nazi Youth organization) is not an argument against Catholicism. It's really only something that can become relevant to a discussion on Catholicism under very special circumstances, such as when someone in Catholicism complains that a particular minister was previously a drug addict or a member of a violent gang, as though that mattered to the truth of the gospel he now proclaims.
Such a claim is absolutely silly, after all. Not only might one respond to such a claim by pointing out Benedict XVI's past life, one might point to true Christians who had serious sin. One cannot forget David and Solomon who both fell into serious and scandalous sin. Furthermore, we could add Moses and Paul: Moses was a murderer and Paul consented to Stephen's death.
But there is another point that the article raises. Sometimes those in Catholicism are so anxious to defend "the Church" that they do not bother to deal truthfully and honestly. An example is Father Federico Lombardi, the Vatican's chief spokesman, who (according to the article) "felt compelled to declare that the pope, growing up as Joseph Ratzinger in Bavaria, 'never, never, never' belonged to the Hitler Youth." (He later backtracked on that.)
That issue is one that is much more germane to the distinctions between Rome and Geneva. The Bible never lies to us, but "the Church" through her spokesmen certainly sometimes does. Now, you can say that Lombardi was simply unaware of the Pope's biography - or perhaps he is simply an incompetent spokesman. The point is, however, that he passionately conveyed a message that wasn't true in attempt to defend Rome and his master, the pope. The Bible does not suffer from that weakness: it is the inspired and consequently infallible Word of God.
N.B. Rome's teaching on infallibility does not state that Vatican spokesmen are infallible. In fact, it hardly teaches that anything Rome sets forth is infallible. But you can trust everything the Bible teaches.