Most of the noblemen who were involved in the plot to strike down the shogunate were executed, and by all rights Tadanobu could hardly have hoped to escape execution either, but because he was the brother-in-law of the slain Shogun Sanetomo, his crime was reduced from the highest and worst degree and his punishment downgraded to banishment.
討幕計画に関与した公家の多くが処刑されており、本来であれば忠信も死罪は免れない状況ではあったが、亡き将軍実朝の義兄にあたることから罪一等を減じて流罪とされたのである。