“Why is his father’s race listed as African? There is no such race.”
The same reason his mom an the twins are fake they’re listed as caucasian. Caucasians are people from the caucasus region of the former ussr. So they should be enlisted as white.
Presumably when statistics were sent to the National Center for Health Statistics or whatever it was called at the time, he was coded as Negro or Black or colored or whatever the official classification at the time was.
State and local authorities weren't so demanding, and in many jurisdictions they'd go by what the mother or doctor or hospital told them. Though birth certificates are official documents there's more leeway than there is on the really official statistics that are sent to the federal government.
That was especially true in Hawaii. The race on your birth certificate might be "Japanese," "Chinese," "Korean," "Filipino," or even "Puerto Rican," none of which are "actual races."
Given how things were at the time, the family probably didn't want to see "Negro" anywhere on the birth certificate and the registrar was willing to comply with their wishes.
I don't know if this thing is real or not, but if you really think the registrar was going to be a hard @ss on this and write in "Negro" or "colored" anyway, you probably don't know Hawaii.