I agree that O'Reilly was a gentleman, but Moore made a valid argument in that exchange. It was not OK to send young people to die w/o better info then they had and no realistic plan to "win the peace". Bush kicked the inspectors out and started bombing and invading at a time when Saddam was zero threat to anyone, and it's not just hindsight. Plenty of people, (including me), disagreed at the time.
Also, FWIW, O'Reilly's demeanor has improved dramatically since getting his ass handed to him by Franken and several others over the "distortions" on his shows, and that is putting it politely. I actually enjoy listening to him now.