At The National this year, Goodwin had several items in his case that had been "sold" in previous auctions. Notably, he had a 1914 Boston Garter Lajoie (sepia), that sold in the February auction. I asked if this item was on consignment and the sales person told me no, it was owned by them.
Lot #22 in the February auction:
http://www.goodwinandco.com/LotDetail.aspx?lotid=9609
Edited to add: I know that random incidents like this might not meet the burden of proof standard in a court of law, but when I'm spending my money, I have a lower threshold.