An usher in the stadium says he thinks it hit the pole. I am a little biased as a Yankees fan but I think the thing nobody is talking about enough if Nate's reaction to the ball he hit. He never reacts as though it hit the pole. He and the umps, aside from those fans, had the best look. Considering he was obviously rooting for it to be fair as hard as he could, I do find it of value that he never argued it at all. He just looks down and goes back to the box.
I am biased though. Hard to tell. Looks like it might have changed based on the replay but there is also a lot of grains and shadows involved as well. If they had ruled it a HR I am not sure it would have changed either.