Well, Donald’s mother was naturalized before he was born, so he meets the requirement: born in the USA of parents both of whom are US citizens at the time of his birth. Cruz might have been a NBC if his parents had filed the required form with the US Console in Canada recording his birth, but unfortunately they apparently didn’t, otherwise Ted would have produced it already. So as it stands, he is indisputably a natural-born citizen of Canada, under their law, as an anchor baby. He is a citizen of the United States under the Naturalization Act in effect when he was born. And he was a dual citizen of the US and Canada until he formally renounced his Canadian citizenship some 15 months ago.
Anyway, it won’t be a problem because Ted is not going to win the nomination.