I'm still trying to get why these guys carried their i.d's. They want their 15 minutes? Proof to their families who will get the $25k?
Maybe they didn't know the bombs were timer activated. Maybe they thought they were just "transporting." Maybe, given the apparant frantic nature of the bus bomber, they didn't even realise what they were carrying.
Long shot, I know. Still, something struck me as odd about this as well, and the i.d. thing got my attention too.