I'm not sure I understand why he would have been killed in a suicide bomb attack. Premature detonation? Mis-targeted by the bomber? Our allies now using our enemy's tactics? Something doesn't add up.
They may have turned on him over the Jordan bombings.
The rumor is that we had some terrorists in a house surrounded, and just as we were going to go in, the terrorists blew themselves up. It was further rumored that Zarcowie was one of them, and that we are trying to find DNA in the house to prove or disprove.
It's only a rumor at this point.
I suspect premature detonation is the most prominant of major factors behind the decision to become a suicide bomber. Feelings of inadequacy are frequently behind abhorant behavior.
If Zarkowi were to have died by suicide bombing, it would be most fitting.
Premature detonation
It can happen to any terrorist.