Voldemort ordered Nagini to kill Snape in hopes of claiming the Elder Wand's ownership.
Let's suppose that Snape was indeed the owner.
In this scenario, would the Elder Wand's ownership truly pass to Voldemort?
I ask this because, after all, the one who overpowered Snape was Nagini, not Voldemort.
- Voldemort ordered Nagini to kill Snape. However, this would be equivalent to ordering a Death Eater to kill Snape, in which case the Death Eater would gain the ownership - in a similar manner, Nagini is the murderer.
- Nagini isn't a "spell": remember how Draco summoned a snake to attack Harry back at CoS? If that snake kills Harry, I'd imagine that Draco gains the ownership (if Harry had the Elder Wand) because that snake was a "spell" casted by Draco - but this time is different, because Nagini isn't a "spell" casted by Voldemort, but rather an actual third-party creature.
The curious thing is that Voldemort did cast some sort of spell (he flicked his wand), which I think caused Nagini's barrier to break so Nagini could kill Snape. In some way, Voldemort did provoke Snape's death - however, it was mostly indirectly.
So, would the ownership pass to Nagini or to Voldemort? If it passes to Nagini, would the Elder Wand's "ownership cycle" end, or would it continue if Voldemort decides to kill Nagini?
The simplified version of this question is: if an animal kills the owner of the Elder Wand, what happens to its ownership?