Since it was never the "official" policy of the Church they can get away without apologizing for it or condemning the teachings that led to it.
Pretty slick, huh?
Are you attributing this "slick" behavior to anyone in particular by virture of them belonging to the Mormon faith?
It is not a "behavioral" issue, it is a "public relations tactic."
The decisions regarding the "official" response to uncomfortable historical or doctrinal questions usually come from unnamed people in Salt Lake City.
Pretending that it was never the "official" policy of the LDS Church to deny the priesthood to blacks, or that it was never the "official" doctrine of the church to assert that Blacks were cursed with the mark of Cain because they were not as valiant in the premortal existence as those who were fortunate enough to be born "white and delightsome", is functionally the public relations equivalent of saying "I did not have sex with that woman".
That, IMHO, is pretty slick PR. Better hope nobody calls them on it, or Romney could be in for some uncomfortable questions when he is running against Hillary (I will do ANYTHING to get elected) Clinton.