THE tragedy took place a week ago, but sorrow was still deeply etched on 31-year-old Mohammad's face. Several times the face of the al-Jazeera TV cameraman, who used to smile easily, crumpled at the lobby of the Palestine Hotel in Baghdad in the middle of last April. It wasn't only because his office was hit by an American missile the week before, but also because he was cut up at the loss of his friend, Tareq Ayoub, an al-Jazeera reporter who