During his fight with Sasuke, it was stated Itachi wanted to push Sasuke past his limit in order to draw out Orochimaru. But how did he know Sasuke had absorbed Oro? The rumor was that Sasuke had killed Oro, no one knew he had absorbed him. If even Taka, who was with Sasuke the most during that time, didnt know, how the hell did Itachi know?