
Visible crew/equipment: As Achilles' ship nears the Trojan shores, Agamemnon snidely asks, "What's the fool doing? He's going to take the beach of Troy with fifty men?" At the start of the next shot, as the camera begins to pan down, on the far right, just beside a person's (who is dressed in blue) head is a metal bullhorn (ie. used to give instructions to cast/crew, and which definitely doesn't belong in this time period). (00:36:35)
Answer: They didn't know the Greeks weren't bringing cavalry. The Greeks did use them and sometimes brought them by sea. It was there to stop a cavalry charge and to break up fighting formations.
LorgSkyegon