It's in his explanation of NRx piece.

Gotcha. Unfortunately, the link to that "sympathetic and extraordinarily impressive defence" is broken. I don't suppose you happen to know of another source for it?

Since we're quoting Yvain, let's continue

It's maybe worth saying a word or two about the context for that quotation: Yvain was writing about the tendency to take "someone wrote a decent-looking rebuttal to X" as justification for saying "X has been refuted and debunked". His argument is not "TBC is in fact right because all these people say positive things about it" -- that's just the mirror image of the thing he's objecting to. It's "You don't get to claim that TBC has been refuted just because lots of eminent people trashed it -- look, lots of equally eminent people defended it too." With which I agree. Which is why I called it "pretty controversial" rather than, say, "known to be bad".