Board Thread:Versus Debates/@comment-26998824-20151210004253/@comment-25122992-20151223155324

Itachi simply meant Kakashi wouldn't manage to do this cause he's not an Uchiha and it's not his own Sharingan. Of course, it'd be a lot more easier to use MS for this task, but as far as I know, BZ explained to the WT that it's not so nessessary (his theory about Sharingan being just a shinobi weapon, and the mastery over it depending on it's user).