They probably didn't know. Ignorance is even more widespread among journalists than bias.
First of all, as a veteran newsman and war correspondent, Arnett, esp SHOULD KNOW that taking and showing such videos of POWs is a gross violation of Geneva Accords. The fact that he said nothing to object to it means that, in effect, he is complicit in its criminality.
TO THE POSTER WHO RAISED THE COMPARISON,
As to comparing an embedded US network journalist coming across and showing how well Iraqi EPWs are being cared for and treated by US/UK forces to the VILE IraqiTV boasting of how they have brutally interrogated and murdered US personel is such a gross comparison, I can hardly speak!
SHAME ON YOU!