Charles Taze Russell agreed there are mistakes in the Bible.
There are certain parts of the Bible that are purely historical. The Books of Kings and Chronicles and the books of Matthew, Mark, Luke and John, are purely historical, and there is no particular need of inspiration in regard to these, unless it would be that divine providence would guide them so that they would not leave out what should be in. But where a history is written, it is not of necessity that it should be inspired, because all truth is good. If Saint Matthew, for instance, wrote that Jesus said thus and so, he is merely telling what he heard, what he knew to be the facts. He did not need to be inspired to tell the truth, any more than you need to be inspired to go out of here and tell what I have said: you should tell it straight; so there is no need of any inspiration about it. Now, I would say there are passages in Kings and Chronicles where evidently an error has been made. These are historical books, and there are little slips somewhere in the way the thing has been recorded. Both books cover the same period of time, but one gives it a little different from the other. We may see some day just how they can be harmonized, but at present we do not.