No, it's talking about professional German officers who were in the German Army for years before the Nazis took control. They deeply resented what the Nazis had done to the army, and to Germany. One of the great tragedies of that war is that the German people, and the German Army, became victims of the Nazis just like everyone else.
Beyond that, which is all true, the irreducible fact remains that Nazis are indeed human. Reducing them to monstrous untermenschen (the irony!) is a defensive attempt to separate oneself from the contamination of evil, but is fundamentally incorrect.
The evil that the Nazis did is part of the fallen nature of all of humanity; the bloodstains on humanity’s hands go back to Cain and Abel.