In book 8 of the Iliad, Odysseus's fleeing shows that he respects the power of Zeus, who's just sent down an enormous thunderbolt from Mount Ida and a flash of lightning upon the Achaeans.
It may not look very seemly or heroic, but Odysseus's mad dash toward the Greeks' ships along with his comrades makes perfect sense. It simply doesn't pay to defy the wishes of the gods, especially not those of the mighty Zeus.
And yet Diomedes, one of the bravest warriors on either side in the Trojan War, doesn't see Odysseus's sudden dash from the field of battle in this way. Instead, he rebukes Odysseus for showing a clean pair of sandals, even going so far as to accuse him of acting like a coward by turning his back on the field of battle.
But Odysseus doesn't pay any attention. He knows that, for the moment at least, Zeus is on the side of the Trojans, and so all he can do is to pay heed to the very visible—and audible—signs of Zeus's will.
Ordinarily, Odysseus would respond to Diomedes's accusations with fury, but given the state of things on the battlefield, he has no time for that, even if he did actually hear what Diomedes said. Instead, he needs to run down to the Achaeans' ships as fast as his legs will carry him.