The Gaetano Amato situation is kind of interesting.

The Genovese did not retaliate because, officially, they have instructed their men to stay away from the war and not to go to Colombo hang outs. So Amato was blamed for being around Colombo guys.

I think the real reason is that Gigante did not want to go after the Persico faction. Not because he likes Junior but because he did not like the idea of putting aside the rightful Boss and he did not want the Colombos to fall into the Gambinos influence.

If the Orena faction had killed Amato, I'm sure Gigante would have ended the war right away and have the Commission rule in favour of Persico. He may even have ordered a hit on Orena. He certainly had a strong case for it.