Why was Wang Bo demoted?

In the third year of Xianheng (672), Wang Bo returned to Chang 'an. Pei Xingjian and Li Xuan chose something with the same code name, and the name they heard was called several times. However, Wang Bo was ashamed to be summoned by a literary genius and wrote a composition. As a result, Pei Xingjian was angered and dismissed as "a famous talent, and there are several noble people." The next year, I heard from his friend Lu that there were many herbs, and he wanted to go, so he managed to join the army. This is Wang Bo's second job. But who would have thought that the second heavy blow was waiting for him. With his talent and arrogance, Wang Bo had a stiff relationship with his colleagues when Zhou Guo joined the army. At that time, Cao Da, an official slave, committed a capital crime, but Wang Bo somehow hid him in his house. Later, he was afraid that things would get out, so he killed Cao Da in private. It was soon discovered that Wang Bo was sentenced to death and imprisoned. Later, he happened to meet an Amnesty and was exempted from the death penalty. However, because of this incident, Wang Bo's father was demoted from the position of Yongzhou secretariat to a toe rank to join the army. As for the specific circumstances of Wang Bo's killing of government slaves, there is no detailed history, and it is impossible to distinguish right from wrong. However, Wang Bo did not care about mountains and rivers as he did after his first dismissal, but cherished the rest of his life. "Wealth is not as good as floating clouds, and time is not as good as feet. Most of my writing ambitions began at that time. ..... care about resigning and pay more attention. " In the second year, although the court restored Wang Bo's original post, he decided to abandon his official position for the people and no longer take office. In just over a year, Wang Bo completed sixteen missing articles in his grandfather Wang Tong's sequel, which was published in 25 volumes. He is the author of five volumes of Zhouyi Drama, Tang Family's Millennium Calendar, Ten Essays on How to Discuss, and Eighteen Essays on Li Bai's Chang Yan. At the same time, he also created a large number of poems and articles. This is the most prosperous period of Wang Bo's creation in his life.