The form Naemanson was filling out didn't ask for "race". It specifically asked for "ethnic origin". They don't necessarily mean the same thing.

I think it's ironic that a modern-day island culture would even care about ethnicity since intermarriages tend to wipe out most ethnic distinctions within a few generations anyway. If a white person rears a child on an island like Guam, the chances of that child marrying another white person are many times less than they'd be in a larger culture like the mainland US.