I think I know what article you are talking about, and from this Salon piece, evidently Moore's statement was indeed given due to Salon's inquiry into the matter. From the article:
In a statement widely circulated by Moore's people after an initial request for comment by Salon, Moore said, "We have an interview with Nick Berg. It was approximately 20 minutes long. We are not releasing it to the media. It is not in the film. We are dealing privately with the family." Moore's camp declined to comment further on any aspect of the interview.
~snip~