This theory mentioned the awkward point of the expedition troops marching and fighting in the severe winter conditions of the northern part of Japan; it is assumed that the report of Yoritoshi to the Imperial Court stating the grand victory over Ezo was exaggerated in order to cover up his disgraceful matter of losing the important official instruments; in reality, the conquest of Tsugaru and Shimokita Peninsula regions to be ruled under the Imperial Court was succeeded by the later expeditions operated by Kiyohara clan, or even later by the Oshu Fujiwara clan.
この説では冬季に行軍が困難であることや頼俊の報告は自分の不祥事の穴埋めをするための誇大報告とし、津軽半島、下北半島までが朝廷の支配下に入ったのは、その後の清原氏や奥州藤原氏によるものとする。