A "well-known later addition?" I've never heard of that and I try to keep up to date on such conspiracies. I've never heard this postulate before now.
So you are unfamiliar with these matters, but that does not make the findings "conspiracies"
The Christian theologian Brooke Foss Westcott of the 19th century said this in relation to John 21:
Westcott writes:
It is impossible to suppose that it was the original design of the Evangelist to add the incidents of chapter 21 after the verses which form a solemn close of his record of the great history of the conflict of faith and unbelief in the life of Christ.
Read the wiki on John 21 for more information on this "conspiracy"
Besides, unless you can demonstrate how it was inserted later, it has no credibility, in which case, it should be presumed innocent until proven guilty.
I think Equinox did quite adequately....
BTW, why do you contend that a book, that some claim is inspired by God, should automatically be presumed innocent (truthful). Do you also grant this honor to the Koran and Book of Mormon?
"Outrageous claims require outrageous evidence" not "outrageous claims automatically invoke special protection and blind belief"