Sometimes a shot animal will lose blood pressure very fast which puts them in shock. They do some strange things then, usually just standing there like they weren't hit.
I once shot an elk 4 times right in the lungs. You could cover all 4 holes with your hand. He just stood there then slowly fell over. His lungs were a mass of jello and the far shoulder was broken. He went into shock, probably at the 1st shot, and just stood there until he died.
