Board Thread:Theories and Speculation/@comment-25645405-20150722123620/@comment-6769189-20150723012715

Considering later in the manga it Naruto and Utakata didn't recognize each other completely invalidates the filler. Unless stated otherwise, if it didn't happen in the manga its filler. Fillers have been happening for years, and have always been ignored by the canon. Canon really isn't a matter of opinion