Earlier quoted context omitted.
"I was just following orders" has already been established as an insufficient defense in the 1946 Nuremberg trials and essentially all later trials against WW 2 war criminals. It is by now pretty well established that crimes against humanity in general and torture in particular are not justifiable.
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?
In what jurisdiction? duress (or necessity in general) is only rarely a valid defence in English law.