Sure thing as obvious as it was....but Carlo blinded by all-consuming revenge for "Sonny's public beating humiliation of him"

The woman [Mrs. Barzini?!] calling Carlo and Connie's home and Carlo refusing to eat the dinner Connie had cooked, among others, was setting the scene -
1. to provoke Connie
2. Carlo to hit Connie
3. Connie to phone Sonny

and gambling on hot-headed Sonny even more enraged that Carlo dared to hit Connie again even after Sonny's ominous warning, rushing out like Sonny did....