If Hitler told a camp to slaughter Jews, it slaughtered Jews.
Many conservative parents whose grown children presently work for the Fed must pray constantly that their sons or daughters will not be blackmailed to do something unconscionable (like for instance stand down when our one of our diplomatic posts is under attack because they were ordered to do so, or bear arms against Americans protesting their government).
It is hard to imagine how a 19-year-old under conscription to the Reich could have resisted doing what he was ordered to do. On the other hand, if he enjoyed it or did not repent, well...
He is not the first German I've met who had been in Hitler Youth, etc., but fled to America first chance they got, got a job, started a family and put it all behind them. I hope his conscience was clean by repentance before he died. That said, consequences here on earth are a separate matter. No winners in Satan's armies.