Regarding the PA, Bart's right: it isn't found in our ancient manuscripts. That an ancient author mentions finding it in some does not falsify Bart's statement. Can we verify Jerome's statement? Nope, though there seems contemporary evidence to support in the form of similar statements by contemporaries. But they all agree that a) this reading doesn't universally appear b) that the PA is debated and c) the earliest evidence of it in John is late fourth century, so technically ancient, but hardly early attestation. So Bart once again isn't wrong in his characterization. One could argue incomplete; but KJV editions usually don't qualify the inclusion of the PA or explain the textual history. Since that is so and the KJV does include the PA, I hardly think that Bart's objection on the grounds of a FACT is a basis to criticize
Since James didn't touch on this point in his rebuttal, I will. First, I'll say that the virtues of the KJV are more or less in the eyes of the beholder, so it's hardly fair to criticize someone for pointing out a few that someone else may not consider a virtue. On the other hand, mistakes are objective. James was not accusing Bart of being wrong in claiming that the KJV has some mistranslated and archaic words in it--it is evident to a typical clear-thinking person that it does--just as it is evident to a clear-thinking person that Bart made mistakes about the KJV's mistakes (and that James himself even made
Now, back to the PA. It is in D 05, and that is one of our ancient manuscripts--Bart himself said so elsewhere, as earlier noted. It's even Bart's favorite ancient manuscript for Mark 1:41, where he accepts its singular reading as original and that of the 'earliest and best' manuscripts as corruptions.