Board Thread:Naruto Discussions/@comment-3568954-20150628110710/@comment-25549954-20150628112144

Sasuke's sword was in close range to Naruto, and Sasuke and Sarada were under Kurama's cloak which was already blocking Shin's weapon so there was no cloak between him and sword it was surrounding above them. Shin activated his Jutsu, Naruto didn't anticipate Shin's attack and that is why it peirced.