I downvoted you and I'm first-gen Nigerian in America. Just about everyone else is in Lagos. I feel very confident, at least as far as educated Nigeria is concerned, that most suspect Africans-used-as-experiments more than withholding-for-white-man.
Not giving Dr.Khan the medicine was the right thing to do.
Having a few people like you talking about withholding-conspiracies that don't really make sense... is better than giving him the untested drug, ends up not working(maybe producing horrible side-effects) and the general public freaks out even more and trusts all the doctors even less than they already do.