I hope they have this on video, and I hope they pursue this. That stuff is so powdery. If people were truly doused in it, it can get into your lungs.
I agree, I think all of them should get checked out by a physician. I would also contact the manufacture of the product to identify the hazardous materials in the product and any effects or concerns about having the product used as in this manner. They should also file assault charges against the guy. Make the police do their job!