Was there a mistake in Naruto Shippuden episode 202 with Sasuke?

Ok.. Now when Sasuke was using Tsukuyomi on C (Shee), he had his left eye covered and had his regular Sharingan in his right eye performing the jutsu.. Now I am pretty sure he was using Tsukuyomi not Susano'o because Susano'o is a physical attack and C was enveloped in a psychological jutsu (genjutsu). Why didn't Sasuke have his Mangekyou Sharingan engaged in his right eye to perform Tsukuyomi which is a M.S. technique? If this was a regular genjutsu then why did he cover his left eye? Or is this a new technique (or a mistake)? Please alert spoilers, I do not follow the Manga too much.