People with a military background normally have spent more time on this than I. Sometimes they have witnessed it or been involved in it.
I knew a military commander who said he lost 35 men on a paratroop drop just because the wind changed. That would make me think about it.
People die. People die all the time.
It can be an act of God (or nature if you prefer). That's really not preventable. Accident
It could be an accident caused by human error, either by the victim or someone else. That, while preventable, is inevitable. ($h!t happens) Careless accident.
And then it may be a conscious, purposeful act, but one of self preservation. Murder? IMHO, not if it's "him or me".
Then there's pure, evil murder. Brought on by a hundred different motivations, but still one person killing another for reasons other than those stated above. Greed. Hate. Convenience.Murder.
It's a tough subject. But 'reasonable' people can usually agree. Or agree to disagree.