The scientists working in Nazi Germany didn't believe they would even be able to produce a bomb given what they thought it required, and thus they settled for a small nuclear reactor. When they were captured by Western forces they had their room bugged and most of their private conversations were transcribed at Farm Hall. They sincerely believed they were at the forefront of nuclear physics and that Churchill, Stalin, and FDR were just dying to meet them. It is true that when the bomb was dropped most were incredulous, and there were some who were "completely shattered by the news" with respect to the deaths caused such as Otto Hahn, who was an opponent of the regime. Others were incredulous merely to the fact that such a bomb was even possible. Heisenberg responded, "I don't believe a word of the whole thing. I don't believe it has anything to do with uranium" while Hahn jeered at him stating that, "If the Americans have a uranium bomb then you're all second raters. Poor old Heisenberg."
Essentially, one thing Adam Becker argues in his book "What is Real: The Unfinished Quest for the Meaning of Quantum Physics", is that Heisenberg and his student, Carl von Weizsacker, purposefully constructed a revisionist narrative of their wartime activities. The narrative is that "while the Americans had built a weapon of death and destruction on unprecedented scales, they, the Germans, had deliberately pursued only a nuclear reactor, being unwilling to build a massive new weapon for Hitler's Reich - thereby placing the responsibility for their failure on their supposed moral clarity, rather than their sheer incompetence."
While the Nazi project to build the bomb was a disorganized mess almost from the start, the Manhattan project accomplished exactly what Bohr thought was required, but was initially pessimistic about realizing. After he was flown to the US he was given a tour around the new facilities that had been built for the project and said, "I told you it couldn't be done without turning the whole country into a factory. You have done just that."
So yeah, there were scientists who did silent resistance such as Hahn, and even a few scientists who were open in their opposition to the Nazi's such as Hahn's buddy Max von Laue, but we should be weary of the sort of narratives constructed by "apolitical" scientists after the fact to excuse their participation with the Nazis. It's kind of analogous to other Nazi revisionist narratives. Of course the Soviets aren't superior in warfare, it's due to their being willing to send hordes of peasants to their deaths! Of course we Germans have the most sophisticated nuclear physics program unlike the US which is a scientific backwater. Thus you see it's not that we couldn't build a bomb, it's that we were unwilling to build such a destructive weapon! If only the Nazi's weren't so gosh darn virtuous maybe they could've won the war!
I’m pretty sure that Demian Maia is also a leftist and supported Lula.