I was reversing from my driveway at approximately 10 pm at night. A car was parked on the nature strip next to the driveway between the side edge of the driveway and the neighbouring property. Behind that parked on the road not close to the curb was a dark green car that was completely obstructed from view by the first car. I reversed and turned from the driveway onto the road and struck the rear right corner of the car. I accept some responsibility for the car accident but was just wondering if I was 100% responsible for the accident or if it is a matter of contributory negligence?