Yes. Yes I would. Because, as I said, it is still B committing the act that leads directly to C’s death. I think you misunderstand my argument; it isn’t the act of pouring that concerns me; it is the person that gets the final blow
In this case to say that B killed C cannot be correct because pouring out poison is doing absolutely nothing. If A had put sand in the bottle and then B pours out sand B definitely hasn’t killed C because his pouring didn’t affect C’s death. So when B poured out poison and there already was no water in it, it is the equivalent of pouring out sand because poison can’t sustain someone in the desert.
What I meant is that in the context of staying alive in the desert, poisoned water that will kill him doesn’t keep him in a better shape then having no water. So while technically it is still water, it is essentially not water in the context of water is what he needs to live
The difference here is that by the water C has no water (that will keep him alive) at all now. If he wanted to stay alive as long as possible, he would not drink the poisoned water.
By the arrow, many things could happen, an arrow doesn’t automatically kill someone. If Z wanted to avoid the arrow he wouldn’t jump off the cliff