Natural Or Artificial

"Lodestar."

Nicholas van Rijn hopes that the supermetals sold by the Supermetals company have been generated naturally, not artificially, because a market in artificially produced supermetals would imply that an alien civilization with a frighteningly high level of technology is intervening in Technic civilization for unknown purposes. That danger has to be investigated. As it turns out, Supermetals mines the supermetals from the remnant of a giant planet orbiting a former supernova. Thus, these supermetals are naturally generated. 

If there had been a civilization as powerful as van Rijn feared, what might it have done? Of course, it might have found some reason to oppress less powerful races or to manipulate them in ways that were detrimental to their own best interests. However, it would certainly have no reason to exploit or to steal from any such races because it would surely be able to produce whatever it needed with its own technology. 

A more likely scenario, I think, is that the more powerful civilization would continue to conduct its own affairs, which might include interstellar travel, while hardly noticing what anyone else was doing. I overheard someone talking about a TV sf series in which space travellers know of parts of the galaxy where an incomprehensibly superior technology operates - and usually avoid such areas. Might this have been the Vorlons in Babylon 5, which I have never seen? If not that, then what?