I'm pretty sure that if there were really a giant unidentifiable craft hovering over an American airport terminal less than a decade after 9/11 someone would have found a way to point something at it.
I am inclined to agree with you, but on the other hand, according to that WikiPedia article the FAA concluded it was an unexplained weather phenomenon. That is easier to believe, but it makes it no easier to understand how no hard evidence was recorded.