Having been in Hitler Youth or Hitler's army in Germany at that time means nothing. I knew another very holy priest, Fr. Karl Patzelt, who had also been conscripted into Hitler's army. He was taken from a Jesuit seminary and sent to the battlefield as a stretcher bearer (because the men sent out to pick up the wounded during the battle often got killed themselves, and seminarians were clearly expendable).
Unfortunately for him, he was captured by the Russian Army and spent 10 years in a Gulag. When he emerged it was with the desire to preach to the Russian people. He changed to the Byzantine Rite and became a Jesuit whose mission it was to prepare for the fall of Communism. For many years, he was the pastor of Our Lady of Fatima Church in San Francisco. He was one of the few genuinely holy priests I have ever met.
Of course--Nazis persecuted Catholics with ZEAL. Hence Pius XII's supposed "silence" on the matter--the more the Church in various cities and countries protested, the more faithful were rounded up and killed.
It was a cult of personality, and most men in Germany at the time were "compelled" to join some sort of Nazi organization--Hitler's Youth just happens to be the one into which Benedict XVI was forced.
A story like that kind of makes you wonder who exactly he met in the gulag.