In 1900, Nobuo IMAI, a former member of Mimawarigumi (the unit of patrolmen in Kyoto in the Edo period), said, 'It was me that assassinated Ryoma', but Tani conversely criticized Imai by saying, 'There is no way Mr. Sakamoto could had been killed by you, who is performing a publicity stunt.'
明治33年（1900年）、かつての見廻組の一人であった今井信郎が「龍馬を暗殺したのは俺だ」と言ったが、谷は「お前ごとき売名の徒に坂本さんが斬られるものか」と逆に非難したという。