In fairness to Clune, the Warriors targeted him in defense. When your half back is making 31 tackles, which in fact was more than Vaughan (29) and Sims (30). In fact they targeted that right side pretty much before switching to the left.
Yes Cluney missed 5 tackles, but so did Ravalawa (made 9 missed 5) and Bird missed 4 tackles (made 9 missed 4) one of which led to the Warriors winning try. We tend to unconsciously ignore their poor defense due to some flashes of brilliance throughout the game.
Not for 1 second suggesting Clune doesn't need to improve his defense, he absolutely does, but he is not alone in that department.