I quite agree that the judges were on something this season. They made a lot of strange decisions.
However, pattern books are for reference and inspiration. They are meant to be utilized. Is every jean that goes down a runway a cheat because they are simply pants that everyone else has made? Granted, the blouse is very unique (and it could have been a mere coincidence) but the point is that if not, he most likely used the pattern guide as a reference and modified the design to be his own. The designers on the show have put out much worse designs that had no creativity in them at all - at least better creative and possibly copied than washed out and boring!