Beck cut off the audio to her . She could not hear him.
It was pointed out in the Dallas Morning News Blog that talk show hosts do this so they can make the person on the other line sound like they are ignoring them.
Beck questions 9/11 see this clip from his show 9/3/09. He has egg all over his face now.
http://www.youtube.com/watch?v=kKBmo5urXt8&feature=player_embedded