Climebear,
I do agree with you and, indeed, the points of law that you raise. I am merely playing Devil's Advocate. However, my point is that this trial will blur that distinction and, if the Doc wins, will render the argument obsolete. (The Doc is after all saying that he believes he will be acting illegally if he goes despite the points you raise) I do not think that is a good move but it is a possibility of the outcome of the trial.
Let's not forget that GCMs are not just military courts but are presided over and guided by Judge Advocates - civilian lawyers/judges of some considerable experience who can decide on the points of law that have been raised; the military members have no knowledge or ability to decide on points of law, just on guilt or innocence. It is also the JA who will decide on punishment.
This trial and its outcome may have massive implications for Service discipline, morale and the future conduct of War - Do we ask for the consent of all servicemen before deploying on operations?
The key point is that I support neither the Doc nor the Goverenment but the Law.