"A big teddy bear filled with napalm and shrapnel" is such a perfect way to describe Abby. Part of what I think is going on here is that Abby is basically Gibbs' daughter. At least that's the relationship they operate under. Gibbs has a parental mystique of invulnerability and omniscience. Tony is her beloved big brother and his job is to emotionally protect the younger siblings, her and Tim. It's a role he has taken on in the past. So in Abby's mind Tim is vulnerable because he made a mistake but she can't conceive of Tony being vulnerable because she can't flip her mind around to view the situation from that perspective. Abby hates change, so she will deny it to the last dregs of her strength.

Tony having this much of his support structure ripped away from him is crushing. Tim's statement that he's going to try to change but it will be difficult for him holds at least a glimmer of hope. Ziva just needs to be bitch slapped.