I agree that intent matters, which is why I wouldn't call things like accidental shooting deaths "human sacrifice" in the strict sense of the word. It's true they're a sacrifice from the perspective of being a thing our society is apparently willing to give up in order to have guns everywhere, but they aren't performed with the intent of bringing about a particular end. So yes, capital punishment can be viewed both ways.

Then there's the deaths of soldiers in war, which is another fuzzy border case. "Nobody ever won a war by dying for a cause; he won it by making the other bastard die for his" -- but generals know their tactics will carry a death price, and pay it in order to potentially achieve the desired end. One difference there, though, is that specific individuals are not targeted for death; another is that if the end is achieved without death, that isn't a failure of the concept, but rather a great victory. Plus questions of the instrumentality of the death: I think it needs to not just be incidental to the actual process, but the means by which the process is meant to be enacted. If that makes any sense.

(Sorry if I dragged you back down a morbid rabbit-hole, here.)