What is odd about Harry's dream?

Harry falls asleep in Chapter 17 and he dreams about the night that he and Michael helped the Special Investigations team apprehend serial killer, Leonid Kravos. What is odd about this dream is that while they arrest Kravos and destroy the demon in life, in Harry's dream, Kravos and the demon got the best of Harry's team and killed most of them. The demon also tore a chunk out of Harry's midsection in his dream.