This is a tough situation. Your only chance could be the existence of the third party witness that says the person coming down the aisle was traveling at an excessive speed. It is also just as likely that both insurance companies will decide that both parties are equally At Fault and let each take care of their own damage.
You are at fault.
Any time the driver who is backing is at fault, in all 50 states.
Well if you were backing in and hit someone then it is your fault. But if they hit you, then it is their fault.
The person backing out.
If you strike him - you are at fault. He can be charged with the No Parking violation but YOU are charged with the collision.
At least in PA, the person backing up is at fault, no matter how stupid the other driver is. My brother got burned backing up and hit someone speeding through the parking lot. to the best of my knowledge, all parking lot accidents are 50/50.
The person at fault would be the one backing into a parking space. Because they are going to look at it as, your supposed to pull into the parking space front first, not backing in. So it would be your fault. But I'm sure that both of you would get a ticket or something else, because they hit you, and you are violating parking lot conduct.
both of you for not looking back
The guy that is walking.
The person backing out. If you were in the lane/road behind them they needed to use caution when backing out.
In most circumstances, the backing vehicle has the greater duty of care and would be found at fault.
If you are driving the backing car, no matter WHERE the other cas is located, YOU are the one at fault if you collide with it.