Other than Madara's conscience, who fought the Tsuchikages, calling the Yata Mirror invincible.There's no proof Yata can block Jinton since it combines 3 elements, not one.
Other than the databook saying all ninjutsu is made ineffective by it.
Other than everything we've ever been told about the Yata Mirror. Essentially.
Don't go full retard.Tsuchikage, having full knowledge on his former master was unable to react to Mu's invisibility
It's made abundantly clear that Ōnoki's back went out at that moment, paralyzing him and impeding his reactions.