Hmm.... It was an under hand tactic... They have one of the assassin as a part of them and the older brother and mother took care of the mafia boss while the hired father and grandfather by the mafia just act out at stopping the leader.... They didn't even fight him seriously....
Hmm well i dont think the old man would really go and destroy everything like that cuz the other clients were inside... though i do see how yours works too... i think they faked the guy's death after because their client changed when the mafia guys all got killed by their son~ Its just the impression that i got xD A race to see who accomplishes the goal first and gets paid...