Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

Anyone who refuses to admit that this hand is an abomination is of the bloodied persuasion. 

As you can see, it is largely the index finger that comprises the jacket hook. Ditto for the mystery man. He's not holding his jacket with his ring finger and pinkie, is he? No, of course not. Those fingers are on the other side, the inside, but how?