Blame Sonny for a lack of appropriate back up for his Father,
Why would you blame Sonny?
Actually Paulie was under Fredo's jurisdiction. When Sonny complains to Clemenza about Paulie's absence, Clemenza says he asked Fredo if he wanted him replaced, but Fredo said no.
He asked that of Fredo as a courtesy since, in Paulie's absence, Fredo would have to do the driving. As the novel says, Paulie was Clemenza's protege; he had advanced Paulie over others in his Regime. Clemenza gave Paulie the Bonasera job and handled his execution. Clemenza was under suspicion because Paulie was of his Regime. Fredo is no where in sight.
