One thing I suspect is, the guy that Ziva called, Hadar?, is a sort of internal affairs type guy for Mossad and Director David and his pet assassin - not his daughter - are under investigation and Ziva is helping.

And I'm choosing to believe that the promo monkeys are messing with the editing and Gibbs never doubts that Tony killed Michael in self defense. If he does, it's a ruse to trick... someone, don't know who.