How does Zeus make important and difficult moral decisions in this episode Book 16

An exciting duel between Patroclus and Sarpedon takes place in Book 16. The two men leap down from their chariots to fight each other on foot, and Zeus looks on in indecision. Sarpedon is Zeus's son, and the man's destiny is to die at Patroclus' hands, but Zeus has the chance now to save him. He asks Hera what he should do. Hera scolds the king of the gods, telling him that if he brings Sarpedon to safety, none of the gods will respect him. Her arguments persuade Zeus, but he weeps tears of blood in pity for Sarpedon, his beloved son.