It’s believed that God gives people free will. Kuehberger and Hitler. What an irony. Saving a life seems one of the better things one can do. It would have been a tremendously good simple act if the people of Europe had saved one person each from the evil enterprise that Hitler created and oversaw.
I think the priest had no idea on how Hitler would turn out.
As for free will, I think God knows that each person will commit certain sins, or have the chance to, but He doesn’t know how it will happen. It would explain free will while at the same time with God’s knowledge of the future intact.