Though, in later years, it is acknowledged that they were falsified and forged due to the questionable content such as grammar that was not used in those days and unnatural use of honorific expressions, it is possible that Kanetsugu's reply received by Jotai really existed and Ieyasu was outraged by that based on the letter sent from Nagamori MASHITA, Masaie NAGATSUKA, and others to Ieyasu and the record of "Rokuon-nichiroku Diary".
当時使われない文法や不自然な敬語の使い方など内容に疑問があるため後世の改ざん・偽作とする見方もあるが、増田長盛・長束正家等が家康に送った書状や『鹿苑日録』の記録から、承兌が受け取った兼続の返書が存在し、それにより家康が激怒したことは確かのようである。