It looks to me like there are two items that Alex has not paid for that he doesn't have. I hope that all of the people who have not paid me for items that they don't have don't add me to the Probation Thread. I would think that would really clog up the Probation Thread.
But seriously, Jon has already fallen on the sword. He doesn't know where the art page is. Alex isn't out any money. They can do a deal for another page or go their separate ways. Same goes for the Stumptown book. JJs punishment should be that he sells Alex the book for what the current market rate is, because that book was a smoking turd within weeks of its issue.
To me there is no Probation List issue because there is nothing to be done. Alex is not entitled to a refund of funds he never paid and he has already said he doesn't want the Stumptown. He got to air his grievance with Jon, whatever the motivation was. The discussion will stay here to "alert" the public of this transaction gone awry, which coupled with Jon's hundreds of successful transactions is a pretty damn good indication of what dealing with Jon is like.