I would prefer that people kept their cool instead of assuming something terrible is happening. That stare probably indicates they were listening for further reason to freak out, and when nothing else was provided, they realized it was just lightening.

Better scenario is if people all pulled out their concealed weapons and started flipping over tables? Or trampling each other trying to get out? Or getting out into a storm where lightening has just struck in an orderly fashion?

I don't get your point at all other than you feeling as if you are smarter than everyone else.