It's unlikely the grandparents "called them in", since that is not the way it was done.
However they were generated by the filing of a birth certificate, even one alleging a home birth, with no doctor's signature, no hospital registrar's name and signature, and with only the signatures of an "information provider", generally a parent (but could be easily forged) and a witness, who would sign where the doctor otherwise would. IF he was not born in Hawaii, that would be the most likely source for the announcement, and would also be the source of the information on the CoLB. That is why the country needs to see the long form. A home birth in '61 for someone from Stanley Ann's background woudl be extremely unusual, but they were not real unsual in Hawaii at the time, for persons from lower socioeconomic strata. It was not yet "cool" to do a home birth.
Very good summary, thanks.
Not only were home birth not uncommon, but we know pretty much how many unattended births there were in Hawaii in 1961 as well as how many births were out of state, but still registered to Hawaiian parents. Two such births, for example, took place in the state of Washington.