'Supernatural event'?

So what, exactly, was "supernatural", or even thought to be so, about the event that was shown in the news broadcast at the beginning and end of the movie (Ari/Dave shooting his other self)? When I saw it at the beginning, I figured it was the ghost-like figure a few feet to the right of the duo of Daves. But at the end, you see a little more of the scene, and it's just a person, with light reflecting off him in a bad way. Nothing supernatural there. Was it the blinding light (which could have been the flash from the gun)? Did someone disappear that I didn't see?