Board Thread:Theories and Speculation/@comment-31099706-20170327120301/@comment-25122992-20170406162931

Kakashi didn't even know about time manipulation aspect, let alone about Tsukuyomi as a technique. Also, it's Itachi who's the user of Tsukuyomi, not Kakashi, thus his words are valued more than Kakashi's because he should know about strength and drawback of his own jutsu. And he said it's possible to break out from Tsukuyomi with the regular Sharingan, which Sasuke eventually proved.