Yeah, well i think Barzini relied on Sonny's explosive temper to come after Carlo on his own. There were loads of cars there to make sure the job was done and not bungled a la The Don. 'Sonofabitch'

Sonny - Well then, business will have to suffer, all right? And listen, do me a favor, Tom. No more advice on how to patch things up, just help me win, please