There is a beef going back to when Paulie was mad at Tony for the lack of support in jail. Remember that paulie was chatting up Johnny sack and became stand offish with Tonys crew. He got back in good standing with Tony when He robbed That old lady's house and took her money.(great sceen prior to the murder). I dont think It will ever be the same with Sil and Paulie. Silvio is like a wash women running to Tony with gossip. He was with out a doubt trying to get Tony to think it was Paulie