Who was in the wrong.....?

At the grocery store an impala was pulling out of its parking space and midway out the parkin a kid ran out in front of the impala and it stopped to avoid hitting the child. As the impala waited for the parent and the child to walk out of the way, it then proceeded to pull out. Once it was fully out of the parkin, the driver switched the car from reverse to drive. When the driver of the impala was about to drive off another car(SUV) was pulling out also and hit the impala on the side hard. Who was in the wrong?