@Nayef, I think what those people did travelling between US and Saudi directly, is very risky. Definitely the airline would have shared information with the countries indicating they have 2 different passports. The Saudi government might not have done anything about that knowledge, but that can change any time in future with a crack down. Once information is in the system, the information is there forever. They would have been wiser to do what you said about Chinese citizens, going through a different country before reaching their final destination. That way conflicting information transmitted by airlines, would have gone to that different country, instead of Saudi.