Bhishma, Drona and Karna are all students of Parashurama. Each one is taught warfare to uphold dharma. But each one remains silent when Draupadi is being disrobed in public. Each one of them justifies, however regretfully, their support of the Kauravas over Pandavas. Ultimately, they focus on rules rather than the spirit of dharma. Ultimately, they focus on their own helplessness rather than the consequences of their actions on society at large. That is why, as Krishna, Vishnu engineers the killing of his own students.
