This virtue signalling where everything surrounding an indigenous people or other minority must be handled with the fluffiest epistemological gloves is really exhausting. Can the author describe his own personal wonder at discovering this factoid (maybe with the same wonder as when he learned about penicillin in fact) without being de facto labeled a racist?

The New Guinea highlanders were equally ignorant of the existence of the Australians, or most of the other peoples outside of the New Guinea highlands. But it wasn't one of the New Guinea highlanders who took the initiative to make the discovery, it was "some random Aussie". So I think it's fair to credit the discovery of New Guinea highlanders to the Australians, rather than the other way around.

A group of people find out another group of people exist and react with surprise. That's not a mindset, it's been happening since ever since there were people.

Jumping at every opportunity to apply a moral perspective just undermines its credibility.

> Coloniser's mindset much? Finding out people live in a place where is not the same as discovering Penicillin.

Well the people living there certainly weren't going to make themselves known to the rest of the world now were they? The importance of the discovery is debatable but it seems that whitey did legitimately make a discovery, sorry to disappoint you.