Actually, from the sound of it, the materials are in a trash bin somewhere. John, even in your story, your dispute was with Amex for refusing to accept your letter of contest, and other than suing Amex (a hopeless cause for the little guy, and even a lot of medium sized guys) you did the best you could by severing business ties with Amex.

My advice is to sit tight, say nothing to the original guy, don't take his phone calls, don't send him anything. If he is going to sue you, wait for it and do nothing else in the meantime, although you might want to consult with a lawyer or two so that you are prepared should it happen. Although contemplating going to law school, that is as close as I am to being a lawyer, but it is my understanding that in some cases making a partial payment (money or goods) can be used against you in court as acknowledging responsibility. So, you think you are the good guy, trying to do the right thing, and the other guy uses it as a wedge to get more out of you than reasonable third party would consider fair.