Suppose You Live near a Thermometer Factory and You Are

Suppose you live near a thermometer factory and you are suing them in court for pollution during one of their spills, where mercury droplets were detected in the air. A witness makes the statement "Yes, I know there was a lot of mercury droplets in the air because there was a rainbow in the air, just like when a rainbow forms with water droplets." Knowing that mercury is a metal and assuming there were really a lot of small mercury droplets suspended in the air please comment on the scientific validity of the statement made by the witness.