that's what I was thinking but I was like no shisui trusted but Danzo may have; you know how he met danzo a day or two before the night of the massacre ( he gave itachi a "choice") but something tells me that after he got shisui's eye he used in itachi xd
I don't think Shishui would do that, however Danzou certainly would and his eye was bandaged already in the flashback. Given there was a time period of around 6months between Shishui's death and the coup d'etat I'd say it's quite possible that he had his eye implanted in that time. On the other hand, I believe Kishi intended to portray Itachi acting of his own accord, despite the fact that Danzou essentially forced his hand.
Danzo using KA on Itachi is not possible cause then Danzo would have made Itachi kill Sasuke as well.... Whereas Shisui knowing Itachi loved Sasuke the most might have made sure while using KA that Itachi protects The Village and Sasuke.... =D =D