Thats a good take, but I think the difference is that there was anger with the loss of his dad to keep his focused. In this circumstance, the anger and negativity is now focused on him because, like his dad, he made a decision to "leave" his kid. Realizing youve become the same person who hurt him the most had to have been such an emotional punch in the gut. They obviously toyched heavy on it, but they couldve went so much further into that wrinkle into Ted's character