I'm not sure if there's anything public (and what I am even allowed to say.)
See https://www.quora.com/Whats-the-logic-behind-Google-rejectin... where he (at least partially) admits that he was bullshitting:
> I want to defend Google, for one I wasn't even inverting a binary tree, I wasn’t very clear what a binary tree was.
See also https://www.reddit.com/r/google/comments/7l5ibp/max_howell_h... for a discussion.