Plot hole: Several: 1. How did Hush get Batman's fingerprints on the knife? 2. How can the likes of Mad Hatter, Zsasz, and Deadshot go through the prison city without being spotted? 3. Why wouldn't Batman suspect Ra's al Ghul of being the power behind Strange once he discovered him in the prison city?
Batman: It was all a lie. There's nothing wrong with you.
Joker: Nice of you to say. But you of all people should know there's plenty wrong with me.
Trivia: Just before Protocol 10 starts, you end up in a giant fight with Joker and a good number of his goons. If you activate Detective Vision during this fight, you'll see that Joker doesn't have a skeleton. This is also true when he's holding Talia hostage in front of the move theater. This offers a hint to how the plot plays out.
Answer: Listen to the fourth Riddler interview tape. He did a psychological profile of Batman, then picked among candidates as to who could be Batman. He's also smart enough to realize only a rich man could afford all of Batman's gear and vehicles.
Rob245