How bad are the chemicals in a chemical powder fire extinguisher on the G's paint?

Here's the story:
Last Friday I am packing up things in my Explorer to spend a week at my cabin. Just as I have loaded about everything into rear hatch of Explorer (rear of vehicle is facing directly into garage with Maxima and G), I accidentally place a heavy box down onto a cheap automotive fire extinguisher I normally keep in the Ford. It snaps the safety pin release and sends about half of the contents out the back of Explorer and into garage with G and Max. Also it had been raining that day as well so there was maximum adhesion. I rinsed cars off as best I could but didn't really give them a thorough cleaning until today. They both have been waxed within the last 2 months and paint jobs look fine so I hope there was not any other damage. I had quite the sick feeling when this happened.

 

Wash, dry, take pictures.

How does the paint feel?

I'm not familiar with fire extinguishing chemicals, but if the paint "looks ok", I'm sure claying + polishing will bring back any luster and slickness lost.