Different cultures have been counting in bases other than base-10 for all of human history.
Yes, the actual article discusses that.
The article, however, is remarkably weak in support for the hypothesis that the people of Mangareva (the "tiny Pacific island" mentioned) actually used binary arithmetic, since in fact it doesn't give any evidence at all that they actually used binary arithmetic. What it says is they have number words for three binary powers of ten:paua for 20; tataua for 40; and varu for 80.
The jump from there to "thus clearly they invented binary arithmetic" is speculation. They state that none of the islanders use binary arithmetic now, and there's no record they once did-- just those words for binary-multiples-of-ten.
Of course a gentleman in the 18th century wasn't the first to use binary.... that's preposterous.
I don't know what is "of course" about that statement. There doesn't seem to be any evidence of anybody using binary before then. Maybe somebody did, but it seen they didn't tell anybody.