Still, I wonder if the test came back negative because the blister gas or other WMD had passed its shelf life and was no longer effective. Why bury the shells if they are smoke screen laying shells or anything other than WMD?
Good point. Here's some more speculation: perhaps these rounds used a binary warhead that mixed the gas on detonation. This liquid could represent just half the reactive agent with the other being who-knows-where.
I would hope the Danes would recognize a single binary component as a chemical weapons material.