Yes, I agree it was a "mistake" - and if you truly didn't send it, that's good that you get the chance to correct.
But, I might as well just be very blunt. I think some people are defending Ross just because others took offense to it. (That would never happen here, now would it?) That's why I used the if this were your business, would you object to the name dropping associated with this letter, with a veiled threat at the end of it?
Take that part out, and then maybe the reference is not so bad... but I think for a letter of this nature, general information is better then saying a "poster at soxtalk.com", for example, "a fan that I have an acquaintance with" or something of that effect sounds better, IMO.