How could someone like the Grand Scholar Zhang, qualified to be part of the history, have his reputation changed so suddenly? There were many examples of this throughout history. When the emperor was not pleased with the conducts of certain chancellors, he would start a defaming campaign right after that person died; at the very least, the campaign had to be organized in the name of the emperor.
Hence, the crimes the Grand Scholar Chen, the Minister Jin Cheng and others compiled against Grand Scholar Zhang were mostly related to the disrespectful conducts toward the Emperor. However, these crimes had to be accepted by the Emperor himself. As a result, these chancellors had to show adequate respect to the Emperor and let him have more control of the imperial court, unless they intended to rebel against the Emperor.