is one piece episode 642 filler?

Law and Caesar Clown are waiting for Doflamingo at the rendezvous point in Green Bit. He then receives a call from Sanji, who is escaping with Viola from Doflamingo's men.

During the conversation Sanji is forced to knock down some thugs when he got cornered in a small alley, he then continues to speak. He tells Law that Doflamingo's resignation is a hoax and that handing over Caesar would not be a trade whatsoever.

Sanji warns Law to leave Green Bit before it is too late.