You've got that slightly confused. The law at the time required that the US Citizen parent have been a resident in the US for at least 10 years prior to the birth, 5 of which had to be after the age of 14. His mother was barely 18 when he was born. If that was in Kenya, he was not a citizen at birth, although eligible for naturalization. Doesn't matter what the parent does or where they live *after* the birth. The requirements are different now, less years are required, but that was the law at the time.
Good, but point being that either way, Obama is not eligible to be President.
Born in Kenya? Not eligible.
Born in Hawaii? Not eligible because of Indonesian laws of no dual citizenship.
Not eligible.