I don't know which version of the Bible you are using for that Luke 23:3, but the King James version says "And Pilate asked him, saying, Art thou the King of the Jews? And he answered him and said, Thou sayest it."
So again, he's not saying Yes, he's saying "that is what YOU are saying." That's why Pilates doesn't sentence him to death: he doesn't make that claim, so Pilates has no proof he is breaking Jewish law. So he hands him back.