Hypothetical, what are the legal issues around abandoning someone to their potential death?

So I'm definitely not doing this, but I'm really curious as to what the actual situation is. I Googled around a bit for this but couldn't find a satisfactory answer. I'm in the USA if that matters, but I assume most countries will have similar laws about this.

So let's say I'm with my friend in some remote area. We have an argument and I get tired of his nonsense and drive off, he doesn't make it back. Am I guilty of a crime? Say if he does make it back but is injured in the process, is that my responsibility?

Say if he wanders off by himself and I decide to just go home. Am I obligated to report him missing?

Say if it's in a different country? Like we went on vacation to New Guinea, had an argument and again I abandon him? If he gets eaten by head-hunters is that my problem?

What if instead of my friend, it's my wife. Does that change anything? Girlfriend?