Avada Kedavra

Someone tell me if this makes sense. I think it does.

So, as everyone who knows Harry Potter knows, the Avada Kedavra curse (the Killing Curse) is irreversible. Meaning, if you are struck by it, you die. You can’t be revived.

But, having just finished reading The Prisoner of Azkaban, I have a theory. That theory is simple: use a Time Turner to go back in time to prevent the Avada Kedavra from being thrown.

Would this work? Well, yes, because you’re going back in time to when the person was alive. But then you have the issue of interfering with the space-time continuum.

So the thrust of my argument is that, although the Avada Kedavra is irreversible, one could simply go back in time to prevent the murder.

Or do I not understand the space-time continuum?