No need to explain go see it for yourselves http://www.narutobase.net/manga/Naruto/392/4(upper right panel just his regular eyes)
http://www.narutobase.net/manga/Naruto/392/11 (in lower left corner he still doesn't have MS activated)
http://www.narutobase.net/manga/Naruto/392/15 (in bottom panel still no MS)
http://www.narutobase.net/manga/Naruto/393/10 (in upper panel still no MS) -_-
Don't flame me because this is a legit plot hole. How the hell is Itachi using Susano without Mangekyou Sharingan?