Native Americans were astounded by European ships. They included accounts of them in their histories. I think the inhabitants of that planet will likewise do the same with the Enterprise
. Personally, I feel there is a difference between a people seeing an alien craft and people being given advanced alien technology.
For scientists, how would a cold fusion device shut down a volcano? And how was that volcano a threat to the planet? Save for the village perched on the slope of the volcano, it didn't seem very threatening to the planet. Super volcanoes are massive - this volcano didn't seem massive to me.