Our direct evidence doesn't completely pan out, because of the uncertainty of the Quirrel reaction, yes. But even without that we have evidence for the underlying theory: ie: AK is Death>Life: the spell and PC2.0 is Life>Death: the spell.

I can post quotes from both of these, in fact, I would argue that the Harry and Moody conversation on Avada Kedavra exists for the sole purpose of including that data in the narrative. Remember, these are Harry's words, a "magically expressed preference for death over life" and the Patronus Charm being cast by "rejecting death as the natural order."