But would not torturing the Shedai constitute unlawful treatment?
The more I think of it Nogura is Patton. Following orders, even if he disagrees with them. Giving the higher-us his unvarnished opinion but carrying out his orders once they're given regardless of the consequences.
It's lucky for Quinn that T'Prynn was given the order to terminate him rather than Nogura getting the order to do it personally. T'Prynn had developed a conscience by the end. Norgura was a solder through and through. He might have disagreed with the order to terminate Quinn but in the end Quinn would have been dead, just like the Orions on the Omari Ekon.