I'm sure when you were learning to drive, you were told (as I was) that when you see a ball roll out in the street, slow down because a kid is very likely to follow. That is exactly what happened here. Actually this looks more dramatic than it was. The ball did roll out in front of the car, but the driver must have remembered her drivers' ed, because she immediately stopped, and only then did the boy run out and scoop up the ball and hot foot it back to the sidewalk.