Big deal. Stop pearl-clutching. He made salient points about cultures who are behind, struggling to develop at the rate of the mainstream. Not racist. Focus on his dumbass son, there is nothing controversial here, just a word that means something different now.
Actually, Mark Carney's dad didn't just refer to First Nations Kids as "Culturally Retarded", he went further and referred to Negro children as "Culturally Retarded" in eastern parts of the U.S.A.
Here you go...