And I respectfully disagree with you. Eastern Orthodoxy doesn't even call the first sin "the original sin" but "the ancestral sin." Furthermore, since EO doesn't make distinctions between nature and grace and thus rejects the notion that grace is antecedent to man's responst to G-d, it could be understood as a Pelagian, or at least Semi-Pelagian, religion.
You might be interested in this one. It’s a good lesson that details the drift from scripture to tradition.