Bonnano at the time couldnt say no because he probably lack distribution set up but Gambinos knew he had best pipeline from Galantes rise and pizza conections. So if they go to him and say we are taking out your main distributer but we can do this this and this Bonnano would have went along. Galante was gonna be hit whether Bonnano wanted him alive or not he took out a few Gambinos and a genovese or two trying to take over the h distribution pipeline and sure as shit didnt have permission to do so. Its my belief if Bonnano could have saved him he would have.