I doubt it was VX. Half the people in that terminal would have been flopping around on the floor like a fish out of water, and the “suspects” would be just as dead as bowl cuts brother.
Maybe it’s a different kind. Maybe in a form that can be smeared on someone’s skin, even just barely, by someone wearing rubber or latex gloves. Imagine coating bullets with something like that!! A hit anywhere would mean death. Obviously the good guys (us) wouldn’t use something like that on the battlefield but who knows what the bad guys might do.