Hindenburg, an unrepentant Nazi, headed the Nazi atomic program.
Hindenburg was the President of Germany, Hitler's nominal boss, until he died in 1934. The head of the German atomic program was Heisenberg. Neither of them was a Nazi. Both of them tried to protect Jews from the Nazis; in Heisenberg's case, at risk of his life.
Heisenberg risked his life protecting Jews? I didn't know that, and it isn't mentioned in
this interesting video. Heisenberg had Jewish friends and was himself called a "White Jew", and hated Hitler, but he was pro-Germany. Even after the War he expressed regret that Germany had lost the War and he seemed to endorse the Nazi concept of a superior race.
In October 1941, while chief scientist of Hitler's atomic research program, Heisenberg met with Niels Bohr who was of course thoroughly anti-Nazi. This famous meeting is a famous mystery, and was even made the subject of the play
Copenhagen. Was Heisenberg hoping Bohr would reveal secrets of the Allies' nuclear program? Did he want (as Heisenberg later claimed) scientists to unify in opposition to nuclear weapons? Did he just enjoy discussing science with his great mentor and father figure? The meeting remains mysterious and controversial. An important relevant fact is that at that time neither Heisenberg nor Bohr thought that an atomic bomb, even if possible, could be built in time to affect the War. Kathy ("Kathy Loves Physics & History") gives her opinion in the above-linked video: While Heisenberg's meeting with Bohr was ostensibly treasonous, it was done with the full knowledge of the Nazi elite and was a test of Heisenberg's loyalty and suitability to serve as a propaganda agent.
The video is 38 minutes long, but Kathy speaks very quickly and covers a LOT of ground. (It touches on a variety of matters: Greta Garbo's role in rescuing Denmark's Jews, the fact the Heisenberg and other German scientists were held captive by the Allies in 1945 with their conversations recorded, and so on. In addition to being one of the greatest physicists ever, Niels Bohr was a brave hero.) If the topic interests, the video may be a good watch.