Is “Ban Gu's ambition in writing history and the actual outcome of his life” true?

In the 'Narrative of the Book of Han, Part Two', Ban Gu describes his ambition in writing history, defining his work as a grand canon to glorify the Han dynasty: 'To narrate the Book of Han, beginning with Emperor Gaozu, ending with the execution of Wang Mang under Emperor Xiaoping... making annals, tables, treatises, and biographies, altogether one hundred chapters.' In the 'Biography of Ban Biao, Part Two' of the Book of the Later Han, it directly records his tragic end of attaching himself to the consort kin Dou Xian, allowing his slaves to violate the law, and dying in prison: 'When the retainers of the Dou family were all arrested and interrogated, Jing therefore arrested and imprisoned Ban Gu, and he died in prison. He was sixty-one years old at the time.' The historical commentary further criticizes him for being able to mock Sima Qian but failing to protect himself: 'Gu lamented that Sima Qian was erudite and well-informed, yet could not use wisdom to avoid extreme punishment.'