What about copyists' or scribal errors in the basic text families? Sometimes multiple copies were produced by one individual reading the Scripture from a "master" document and a group of scribes writing down what they heard. Obviously this lead to variations of spellings, punctuation, capitalization and the like. Sometimes marginal notes might be incorporated into the text even though they could either be textual corrections or simply thoughts of a scribe. Sometimes a scribe would inadvertently add what he thought he was hearing based on his knowledge of similar passages. In checking such work another person might later add what he thought it should say.

By comparing various copies the correct rendition is more likely found. The additional passages found in the Byzantine-derived KJV do not alter the theology or create a contradiction with other portions of Scripture.