I choose "can't decide" due to lack of evidence.
Key factor: Terrorist are looking for mass destruction and although this could be labeled as this, I do further believe that the "substance" that are causing the illness is not "pure deadly like". Mind you, "terror like" in a mass destruction way.
Then again, we know terrorist act like this so why would they do the obvious? I would think it would be a light demonstration of how the can contaminate our products without anyone noticing.
So, I still stand by this until further evidence is shown.
PS. BTW, this conversation was held by 4 middle aged people that I was listening in on.