Even if Rosa had successfully killed Leonardo DeVille, Gianni would still have punished her severely. If not for anything, but for the fact that she deliberately disobeyed a direct order from him and also to make her as an example to others who might also be thinking they would disobey him and get away with it. And just as he would have punished her, so would he have rewarded her for a job well done. Who was he kidding? He wanted Leonardo dead afterall and disobedient or not, she achieved that for him
But that wasn't the case. Not only did his bitch of a sister have the guts to betray him by teaming up with his arch enemy, the real problem was, that they underestimated Leonardo and because of that, they couldn't successfully carry out the revenge he warned her against. Now they left alive a very dangerous man and left him to deal with the aftermath. Leonardo was only after their grandfather before but now Gianni was sure he would come after all of them, him especially
