i refuse to believe that a an entire killzone 1 level had only 10-15k polygons. thats just silly. the poly count of killzone 2 characters is just noticeably higher than any other game out there. so i dont really believe that guy. and seriously the jak and daxter both have 10k polygons in jak2+. that statement says alot about this guy's credibility.
Its becouse they count the polygons in the non normal mapped character which they are going to extract normal maps from. Just taking a close look at KZ2 you see hard edges and not "that" high polygon count. And remember that Jak2 didnt use normal mapping for character, a technique to give impression that there is more geometry than it really is.