what combination of lucky events results in crusoe being able to gain his freedom

An opportunity presents itself when his master sends Robinson, along with some Moorish youths, to catch some fish. Robinson secretly stores provisions and guns on the ship. They set out to fish. Robinson convinces the helmsman that they will find fish further out. He goes behind one of the Moors and tosses him overboard, saying that he should swim for shore because he the narrator is determined to have liberty. Robinson turns to the other boy, called Xury, and says he must be faithful or be tossed as well. Xury resolves fidelity and says he will see the world with Robinson.