Let me begin by saying I am neither a pilot or an air traffic controller. I think the reason this story has captured so much attention is the language the pilot used, saying "right over the top of us". To me that sounds like he is reporting a near mid-air collision, and I think a lot of others also believed he was reporting a near disaster. The potential of a mid-air collision between an airliner and unmanned missile catches peoples attention and generates fears. The fact the controller did not instantly ask what the miss-distance was makes me think however that this is just routine pilot speak. These days communications like this are recorded and listened too, a bit more precision in the language used, like how much higher the object was, could have turned this into a non-event. As it was people could read in their worst fears as to what almost happened in the skies that day.