From Season 7 Episode 2 - Reunion.

Ziva: Hello Abby.
Abby: (turns music off and glares at Ziva) What the hell is wrong with you? How could you have doubted Tony, after everything you guys have been through together? You really think Tony killed Rivkin because he was ‘jealous’?!
Ziva: Abby, please calm do-
Abby: You weren’t thinking! That’s right, you weren’t thinking! Although… I suppose I could understand your initial reaction… you were in an emotional time for you and people act rashly - but to tell Gibbs you didn’t trust Tony?! Which… I guess I could also understand, considering....