Adam and Eve and the logic failure in the 'Fall'

It is well to be aware of  paradoxes that necessarily attend any attempt to narrate the origins of the Law. 

The Judeo-Christian myth of the fall succumbs to precisely these paradoxes,
 as Kant analyses: if Adam and Eve were purely innocent, how could they have been tempted?; if their temptation was wholly the fault of the tempter, why then has God punished humans with the weight of original sin?;
 

but if Adam and Eve were not purely innocent when the snake lured them, in what sense was this a fall at all?