Errors in the Holy Scriptures?

How could a scribe forget a complete verse in the Lord's Prayer? In fact, the last verse is missing from the Gospel of Luke in both the Codex Sinaiticus and the Codex Vaticanus. So that's two scribes making exactly the same mistake in two completely different manuscripts. It's very unlikely!!! What's more, the last verse is missing from the Gospel of Matthew as well, in both Sinaiticus and Vaticanus.