Eh. You don't have to be the first person to discover something to discover it. This is what people always miss with the vapid line about Columbus not discovering the Americas. Sure, there were already people there. But the vast majority of the human population in 1492 was ignorant of the very existence of the American continents. And their discovery instituted an epochal change that upended both the Americas and the old world.
We can condemn genocide and displacement without becoming pedantic gotcha warriors.
If all that matters is the first person to discover something, no scientist in human history has ever discovered anything. After all, relativity was probably first discovered 5 billion years ago by some alien physicist living several galaxies away.