Board Thread:Naruto Discussions/@comment-28846843-20160625201600/@comment-7292165-20160702030437

It was never said he could perform every jutsu in Konoha, but has knowledge of all jutsu in Konoha, and thus with that knowledge, he can find the best way to counter to the techniques. Though due to his exceptional ninjutsu skills, it can be assumed he can perform every non-kg/hiden technique of Konoha.