Wasn't Paulie one of the first ones to hop up and say 'Kill Vito' after they found out he was the one giving the head not getting it?

"Fredo -- you're my older brother, and I love you. But don't ever take sides with anyone
against the Family again. Ever."

"My father taught me many things ... keep your friends close, but your enemies closer."

"I know it was you, Fredo. You broke my heart. You broke my heart."