Tony sabotaging Ziva's relationship. I can't figure out why, in this scene, Tony referred to Rifkin and Ziva's relationship as not kosher? Ziva and Rifkin cut from the same community, family tree, lineage, etc. That's about as kosher as it gets regardless of race. That lineage is like the sands of all the seas.
I saw this season in 2009. The whole point Tony was trying to make was that Israeli intelligence officials are using her to commit crimes in USA when it was not legal and using Ziva as a cover to throw NCIS off. Michael never loved Ziva in real sense. It was just another ploy.
Kosher refers to their Israeli heritage. Just like Rivkin's "Agent Meatball" is a jab at DiNozzo's Italian heritage. I think at this point NCIS suspected that Rivkin was responsible for killing an American government agent. This had nothing to do with Ziva's relationship with Michael. Tony was doing his job.
