My theory on the whole BC thing is that he was born in Hawaii, but there’s no father listed. His last name is Dunham. Puts the whole “Dreams of My Father” in a different light. And makes sense why he wants to hide it. But when it does come to light, which it will when there’s a big enough uproar, people will focus on the fact that he was born in Hawaii and not on the fact that his whole life story is a bunch of crap.
Alternatively there is no BC because he was never born. He was literally made for the job in some Chinese lab.