Ok, from my point of view, the dark saddles are the tip off. Pure hogs don't have saddles that dark or defined. Look at the picture of mine again:
http://www.glassreptiles.com/picture.../rob042606.jpg
He appears to be a cross of some sort..Again, he is beautiful and this shouldn't make a huge difference but if he sold him to you as a pure hog, I don't believe he was telling the truth. Some closer pics would be better though.