We were advised that there was no guarantee the Court Martial will agree with you, and we were counseled to be FReaking sure that the order was illegal before disobeying it. But if one believed the order was illegal, then one not only could disobey it, one was bound to do so.
And it worked out so well for New and Watada, didn't it? The military takes a dim view of personnel who decide for themselves if an order is legal or not.