Because the attack was outside the Inca's experience and understanding, they had no response framework to draw on; their fight-or-flight instinct took over, and they fled.

“plays out in a way that they have no mental”

“appreciation of or able to draw back any kind of library of how do I respond in this situation the fight-or-flight instinct just completely takes over and and the flight was the winner in this instance as you say the only casualty was Pizarro himself he's reaching for Adewale to take him prisoner and one of his more enthusiastic comrades slashing and manages to cut his hand as he does that that was the only injury any of the conquistadors suffered at this critical moment”