Mario Puzo and his Italian heritage

does anyone feel that it would've been presumptuous for a non-Italian author to write a novel dealing with the Italian underground (considering when it was written). there is another author, eric lustbader, who often writes about the oriental underworld, but he is not close to being asian. anyway, his stories are mostly quite horridly vivid, but albeit of substance. i was just wondering if any asian would take umbrage to lustbader's writing (e.g., the ninja, white ninja, etc.)