Don't you believe that the bread and wine miraculous changes into the actual blood and flesh of Christ? Why then it is so difficult to believe that God could ensure His word remained "unfiltered" and "unaltered"? If God can change the elements can't He maintain continuity in writing? The early church fathers believed this.
The message of the Bible remains inerrant. For, when one delves deeper into the "contradictions" that appear in filtered and altered words and paragraphs, one finds that they are not contradictions.
Now, as for the Eucharist, the Orthodox do not go into the mechanics of it. To me, His real presence is in the purity of the bread and wine. In other words, in my limited mind, this becomes possible when they are cleansed by the Holy Spirit to the same degree as His Body and Blood are, and thus they become a substance that is Him in essence.
I would say that by a similar mechanism beyond our comprehension, the word of God remains undefiled despite our corruption and errors which we bring into it by copying and translating, and interpreting.