John McFarlane, the leader of ANZ Bank, proved to be a successful leader by increasing customer satisfaction rates, staff engagement, and community recognition, while also turning around the financial performance of the company. He demonstrated knowledge about operations, involved stakeholders, and analyzed market trends to make informed decisions. As an organizational leader, John played a crucial role in implementing change management programs at ANZ, which included researching areas for improvement, establishing trust with stakeholders, and designing a performance management system to analyze progress and reinforce successful changes.