That wsj article, and the yahoo writer they quote etc have it wrong. At the end of Feherty's interview of SW he asked a long question which took about 20-30 seconds for DF to get out, but it was in essence this:"Of the victories you've been on the bag of, this one must be one where's you've been able to have a hand in forming the golfer, right?" and SW in answer says a few things and at the very end:“It’s the most satisfying win I’ve ever had.” But it doesn't seem to me he was making a blanket comparison to Woods 13 victories for which he was on the bag. The context of the question came into play.
Interview video, the DF question ends at about 5o seconds
Steve Williams on Adam Scott's Victory - YouTube