I didn't mind how it ended, just felt they didn't quite pull it off. Certainly hinted that Buckles wasn't the top man, but everyone will be satisfied by him being the 4th Man. OCG likely to leave him alone as he is taking the hit for it all, and the police can sweep it all away. Just like everything else the police have ever been accused of, and considering the clear endemic racism in the police, I found it an apt ending. Everything goes back to the start and carries on like nothing happened.
They didn't quite pull it off storywise though.