How did it miss the person? You couldn't see them?
Our new car has quite a wide angle on the camera, our older ones didn't have that. But for sure it's something you use in combination with looking, the reversing camera is for directly behind where you can't see with mirrors. You should still turn your head as well to check traffic (and people) coming from the sides. You also look in your side mirrors too. You don't just pick one.