Did I just miss it, or did the write up not address exactly how the dealership came about getting the truck? Trade-in? Auction? Direct buy from the previous owner? In any case, the due diligence must have fallen totally through the cracks. You can bet there's a LOT more to the story than we will ever know.
And BTW, "daddy always said you can,t trust a sales person." goes down as the most ignorant response to a post today. You can rest assured the salesperson had nothing to do with the acquisition of the vehicle.