A divorce decree for a bigamous marriage is as null and void as the bigamous marriage!
Thats gonna require an investigation, an international investigation. Thats a tough row to hoe.
Otherwise it is speculation.
What was the point of BHO flying to Hawaii around 1972 to visit with SAD and little Barry? I believe it had to do something with re-instating BHO as the legal father (thereby reversing the adoption by Soetoro), was it not?