Now I'm really confused.
Okay, so Batgirl takes down Shiva before the events of Infinite Crisis. With Shiva out of the way, the League of Assassins have no leader (what with Ra's and his oldest being dead, and Talia raising Damien and running LexCorp (wait, isn't Lex running LexCorp? When did he take it back?)), but that's not when Cassandra takes over because she's still out as Batgirl two weeks before the events in Robin: OYL.
In The Titans East storyline of Teen Titans, Deathstroke reveal(implie)s he has control over Batgirl, thanks to his specialty drugs like the kind he used on Rose and may have taken recreationally with Terra. She was quite the minx, for jailbait that is. Anyway, here's where WWIII screws up everything.
If Batgirl was talked into betraying the Batman Family, why did the Deathstroke drug antidote make her change back to the light side?
If Batgirl was drugged into betraying the Batman Family, why does Deathstroke do the whole devil-on-your-shoulder speech in WWIII?
How does Batgirl have to the time take total control over the League of Assassins and set up Robin in the two weeks before Robin returns to Gotham?
How can no one pick up on how this fucks up this whole character arc?
And wait, when the hell did Kid Devil and Ravager join the Titans when they weren't there two weeks before? Who was on the team when they got there, because this is what drives off Raven and Beast Boy apparently, yet no one else on the team that fought Black Adam stayed?
Damn, DC, now that I think about it, 52 failed miserably.