How do you know Long John silver was impressed in the end by Captain Smollet's moral code? (Chapter 20)

Silver opens the negotiations by saying that he thinks that the pirates should be given the treasure map. In return, he will divide the supplies and take them on the ship and put them at the nearest port, or tell the next ship he sees to come and get them. Smollett, disgusted with Silver's proposal, makes a counter-proposal, claiming that if the pirates come to him unarmed, he will put them in shackles and give them a fair trial. Adding insult to injury, Smollett points out that the pirates are powerless - they don't have the map and they are also on the wrong side of the island, "on a lee shore," the side that is away from the direction in which the wind blows. In conclusion, he orders Silver to leave.

As he leaves, no one will give Silver a hand up. Furious, Silver crawls along the sand until he can grasp the porch and then hoist himself up. Retaliating, he spits in the spring water and promises that he will destroy them within an hour, those who die will be the lucky ones. He then departs, but not without extreme difficulty.