Regarding the documents cited as evidence, the "Roshi (masterless samurai) Bunkyu Era Patriotism Articles" (a diary written before the "Tenmatsuki") by Shinpachi NAGAKURA which was discovered later does not describe 'the Uchiyama assassination' and the "Tenmatsuki" seems to have been dramatized by Nagakura himself and an editor of 'Otaru Shimbun' in which the "Tenmatsuki" was serialized, while Kanefumi NISHIMURA who wrote the "Shimatsuki" bore ill will toward Shinsengumi and therefore both documents lack credibility.
根拠とされる書物も、後に発見された永倉新八『浪士文久報国記事』（『顛末記』以前に書かれた日記）では「内山暗殺事件」について触れておらず、また『顛末記』には永倉自身ないしはそれが連載されていた「小樽新聞」編集者によると見られる脚色のあとがあり、一方『始末記』の西村兼文は新選組に悪意を持っていたため、共に信憑性を欠くというわけである。