444throwaway

True, but they did not decide how to do it and did not implement it. I would expect the facebook engineer who implemented it to be able to explain it to me, at least the part which he did.

If we can't ask the AI to explain how it came to its conclusion it is not really intelligent, is it?

You would not believe a human is intelligent if he just tells you what to do without being able to explain why, would you?