How is even rewriting what a disciple wrote or anecdotal witnesses proof of accuracy? I think the acceptance of ultimate authority of any bible would be in the eyes of the beholder. I mean if a dude walked up to you now and claimed to be the 2nd coming of Christ would you just believe him or question him pretty much as the ancient Jews did? Ones faith is unique to them, and for many using what's in the bible as proof of its authority is not enough, nor is the finding of ones faith tied to a book even if others believe it so.
I have always felt personally that asking a person to follow a book or suffer consequences was a threat rather than an invitation. Yeah, I know, I'm just a heathen, damned to hell for no faith in the words of ancient man, scholars (Flawed humans that could read and write), or true believers. How dare I question the veracity and intent of such a dedicated lot.