piecing some statements together here . . .
the IED exploded before it could be rendered inoperable . . .
"The round was an old binary-type requiring the mixing of two chemical components in separate sections of the cell before the deadly agent is produced," Kimmitt said. "The cell is designed to work after being fired from an artillery piece."
From the first statement, I would conclude that the soldiers were attemting to disarm the IED and that it exploded.
In conjunction with the second statement, it seems unlikely that the sarin would have been created by the detonation itself [chemical agents are very hard to dispurse under ideal conditions - explosions generally destroy them instead of creating them!!].
Maybe there are a few experts here (I was in the Artillery in the early 80's, but this was not my expertise!!) who will correct me, but, the sarin needed to have been "mixed" prior to the detonation which indicates both a foreknowledge that the round contained sarin AND the knowledge of how to mix it properly . . .
Correct me if I'm wrong (and I very well may be), but don't chem-laden shells have a VERY small amount of explosive in the nose? Just enough to 'pop the top' so the chemicals can be released?
It is the actual shock of firing the shell from a gun tube that mixes the chemicals together to create the active agent. With the two reagents unmixed, the shelf live is much longer than 5 years. So this could be a shell from the 80s. It is still a lethal weapon, worthy of the moniker WMD.
BTW, atropine is a lethal poison. Left untreated, atropine poisoning is uniformly fatal. This is a case of the cure being only slightly less dangerous than the disease.