The point is, an advanced computer with an infra-red and radar tracking system can see a deer or a thousand deer long before a human can, whether the deer is/are at the side of the road or in the trees. It can then modify speed to minimize the threat of such animals. If the animal becomes a danger, a computer will not react in shock as a human would, but will calculate all the possible movements of all the deer that are dangers or threats. It can also calculate the state of the road, the health and abilities of the car's systems, positions and movements of any other vehicles, positions of obstacles and all possible variables. Then it can choose the best course of action to minimize harm - all in a few milliseconds. A human cannot come anywhere close to that.