in this case, since it was a domestic flight, I wonder if the better strategy would not have been to let everyone board, and then taxi the plane to some remote hangar at Dulles and let it sit for a while. Monitor the cell phone calls coming from the plane as it sat there, and see what shakes loose.
There has been a lot of talk of biochemical attacks today on the news. So that might be a reason for not letting people board the planes. Jay Rockerfella has been on Fox News today and Fox has repeated the interview where Rockerfella states that we do not know how and cannot stop a biological attack.