indeed, that is the key now - finding the depot where this one came from. it must be part of a set of them that was buried, now dug up by the insurgents to use in IEDs. We must find that depot.
To look at this another way...
How many shells were looked at by both our people and the UN and assumed to be HE, but are actually chemical weapons? Unless you actually take the shell apart or weigh it, there is no way to tell. A visual inspection isn't enough.
Something to think about, Mr. Blix, eh?