Glenn writes (among other things):

Actually Barbara never said she "heard the typewriter comment directly from Ayn" in her book. Three years later N. Branden said Ayn told "us" but doesn't identify Barbara.

In the column to which these responses are a response, Barbara writes:

What I did not mention, because I did not think that Fern’s story would be questioned, was that I heard the identical story from Ayn.

I submit that nobody on the planet earth, researching and writing a biography even of the wisdom and authority of The Passion of Ayn Rand--no matter how prescient, no matter how clairvoyant--could possibly have gained access to the kind of infallible crystal ball that would allow the author to anticipate in advance not only all possible corrections to her ground-breaking book, but also all possible ways any error, or minor or irrelevant omission, might be employed to "prove" the author's alleged manipulativeness or dishonesty.

The cavils, counter-cavils, and counter-counter-cavils are not adding up to any persuasive disproof of Barbara's conscientiousness in researching and crafting the story of Rand's life. If I were Barbara I would not be very inclined to respond at any length to even legitimate queries and observations, given the ill-tempered and gratuitous gotcha tone of much of the fault-finding. I don't need access to the parallel universe in which any particular one of these critics has written the first book-length treatment of Rand's life to know how it would compare to what Barbara has accomplished.

Let's try to remember that a) Barbara Branden did write the first-ever full-fledged biography of Ayn Rand, doing a masterful job; and b) Barbara Branden was not allowed access to the papers of Rand in possession of the Estate of Ayn Rand/Peikoff. It is a powerfully inspiring and informative book despite that lack of access. Is there any initial major biography in the history of biography that has not been in part corrected, updated, refined by later work with the benefit of further thinking, testimony, and documents?

Let's enlist a little perspective here.