I think you may be getting your carte blanc before your Camel. :)
I read "the Camel" and I don't believe it mentioned any such thing (probably not the same revision of "the Camel" you refer to, of course). And at the time (quite a while ago) of the coming out party of the "It is documented. Duh!" proclaimers, I don't believe it was documented well in a popular book. In any case, I never saw mention of documentation of that in books in that time frame. I'm not at all surprised that it is documented in some books by now. But I also wouldn't be totally shocked if there was a book that covered it well way back then.
But it is also true that bugs get documented in auxillary reference material. The "It is documented" is more short-hand for the "We can't change it because the standard documentation has always said that it worked that way" claim, and that is the meaning that I call "bull" on.