Why Did O'reilly Just sit there when Jon Stewart pointed out Fox News Hypocrisies w/ musicians invited to the?

Jon Stewart debated O'reilly this week on " The Factor", and at one point in the debate, Jon Stewart pointed out Fox news' " Selective outrage", and he named 4 or 5 other Performers who have been to the white house in recent history, all who have written songs about " Cop Killers" and " Murderers", all of whom Fox News never disputed or pinned the blame on the President over. When these facts were brought to the conversation, O'reilly would just spit out some insult and talk about something else. It's like he refused to acknowledge the fact that the network overlooked all the visitors when Bush and Reagan were in office. And he would not directly respond to it. Why wouldn't he respond to that?