What about when it is combined with duress? Like if you refused once and were told they would kill your family if you ever refused again or quit? I'm just curious. I agree with the spirit of the idea that following orders is not valid justification, but being under duress is a well-known and generally accepted justification for committing a crime. Can you shed any extra light on this?
War criminals who would have been shot for abandoning their posts (almost all of the low-level guys fall into that category) have been, and continue to be, prosecuted for those crimes. It's not a hypothetical, it's still in the news.