Similar examples? Well, when I was taking Command & General Staff College course (1987) (think of this as the Army's version of a Masters Degree in Military Science), one of the readings we were assigned told the story of a British unit in Burma that had to leave some severely wounded behind. They had to retreat across difficult terrain. These wounded would not have survived the journey and would have suffered extremely none the less. The head doctor for the unit administered lethal doses of morphine knowing that the Japanese would use them for bayonet practice.
Is it routine? No. Does it happen? Yes. This officer's mistake was to talk about it afterwards. Very poor judgement on his part. Not only for his own sake but that of the officer he told. Telling his fellow officer was very unprofessional since it forced the fellow officer to either bring charges or to become an accomplice after the fact. One does not place your fellow officer in such a position.
My impression was that the other officer was there, and was a witness. But even so, it does place that other officer in the awkward position that you describe. It has to be written up, or he puts himself at risk later.
It's tough. I really hope that the CM returns an acquittal if the facts are as reported. That's the right thing to do.
Right!