You're asking for something that doesn't make news. There's multiple classes of this.

The untold hours NCOs and officers spend sweating details to reduce moral ambiguity in operations.

If you want is to see men take bullets for innocents, there are plenty of them but, unfortunately, there aren't many people around to tell those stories. A few have made it out, and you can find some of them in the Medal of Honor citations (1)

General Dean's delaying action at the outbreak of the Korean war (2).

More subtly, General Shinseki testifying to Congress against administration dogma on the number of troops needed in Iraq, and sticking to that despite intense pressure.

Admiral McRaven's life in general.

(1) https://smile.amazon.com/Americas-congressional-recipients-o...

(2) https://en.wikipedia.org/wiki/William_F._Dean

(3) https://www.nytimes.com/2007/01/12/washington/12shinseki.htm...

For a discussion about morality and, arguably, lack of morality at an extreme level (strategic nuclear war plans) - worth considering the discussion between Marine General David Shoup and Air Force General Power:

https://www.dailykos.com/stories/2007/3/22/314933/-

"any plan that kills millions of Chinese when it isn't even their war is not a good plan. This is not the American way."

I don't think that is a reasonable question.

To use an extreme example: I can ask for a examples where someone has committed murder, but it would be unreasonable to ask for examples where someone hasn't committed murder.

There's an asymmetry to showing morality or immorality. Exhibiting a sense of morality is the standard case, and it's hard to show it. Being immoral, however, can be trivially shown by pointing out the mos or law being broken by a specific behavior.

I think the question is very reasonable, your example is flawed because question is not about examples of someone not doing something, he is asking if someone actively worked against or seriously questioned of a murder he/she is ordered to commit. Parent is sceptical because of priori contrary evidence that military actions and morals conflict frequently.

> he is asking if someone actively worked against or seriously questioned of a murder he/she is ordered to commit

How could one reasonably produce publicly available documentation where someone refused to execute an unlawful order? Why would someone issue such an order in the first place?

Think about what could possibly motivate a soldier's action: the consequences of questioning an order are far less severe than the consequences of executing an unlawful order. "I was only following orders" has long been discredited as a legal defense.

> Parent is sceptical because of priori contrary evidence that military actions and morals conflict frequently.

Morals are not universal. To which morals are you referring specifically? Some people are morally opposed to violence in principle, the military obviously is not.

[Edit]

I'm still in disagreement as to the logic of the question, but I am beginning to think that the mere existence of court martials in the interest of upholding military law (ie, codified morals of the military) should be sufficient proof that a military body can exhibit a strong sense of morality.