Everything was right, huh? Shisui's genjutsu wasn't recognized as what controlled Yagura. It was stated to be similar. It was Ao who saw through that genjutsu. A Uchiha actively part of Konoha mind-controlling the Mizukage? Yeah, there'd have been some shit goin' down over that.
Obito said "almost smashed", not "completely crushed":
http://www.mangahere.com/manga/naruto/v27/c243/14.html
That kid would've been personally trained by Madara, knew the secrets to the Flying Thunder God, and awakened the mother of all MS abilities.