OutSurrance not taking 100% resposibility

On 1 Jan 2015 I was driving in a parking area on my way to a main road. As I was driving an OutSurance client reversed out of a parking area into my vehicle. He crashed into my side at the right front wheel. A claim was submitted at OutSurance by the driver of the other vehicle. OutSurance feedback to me was as follows: they will ONLY pay 60% of the damage caused by their client the reason being That I should have looked out for vehicles reversing out of the parking. How ridiculous is that. I was already passing their client when he decided not to look behind him for the vehicles passing. OutSurance do not want to take 100% responsibility for the mistake by their client and now they want to claim that it is my fault. It may be that they are contributing to their bonuses by saving and not paying 100%. Classic passing the buck and putting blame on non clients.