By Chris Rosvoglou The initial belief around the NFL was that Patrick Graham would return to his role as the defensive coordinator of the New York Giants. Instead, he decided to join forces with Josh McDaniels on the Las Vegas Raiders. According to NFL insider Jordan Schultz, the Giants were “stunned” that Graham left them for the Raiders. “Giants believed Patrick Graham would stay on as DC and were stunned to learn he was going to the Raiders, per a league source,” Schultz tweeted on Saturday afternoon. Earlier this week, Giants owner John Mara said the team would like to retain Graham as its…