I'm so cross with Voldemort! How could he have possibly left Harry with the wand? How could he? It's the exact sort of mistake he obviously wouldn't make, especially since he already demanded Harry's wand several times already. How could he have left Harry with an hour on the time-turner? The game was going to last all night, it would have been so easy just to use up all the hours. Why did he wait for last words? See points 14 and 16 on the supervillain list: NO last requests, NO last words. It's all so weird and uncharacteristically unlike him!