Rapa nui (and other Eastern Pacific Islands) hadn't been settled yet at that point, while indigenous Americans were already building monumental structures (e.g. Norte Chico) and working metal (old copper complex). The latter predates most metalworking in the old world too.
Their settling is irrelevant as long as they were able to get there. It's possible that they brought the ideas to Norte Chico where a civilization developed before them settling down.
