This question extends to other organizations as well.
Very often I read some sort of apology for this people. It goes mainly like this: "You were not there, so why would you judge them?" or "If they said no, they would be killed as traitors". I my opinion that´s a very bad argument against judging people in Nazi Germany. But besides of that. Is there any truth to that? And I explicitly ask after atrocities.

My first thought is No. You wouldn't be shoot is you said no (or fired into the air). It would be bad for your career. And if you elaborate (Wehrkraftzersetzung), especially in the later years of World War II you could be visited by Gestapo or SD officers.