I had a car accident last week. The police had closed the road and an officer was stopping traffic to ask drivers to turn around and go back the way they came. It was a narrow road and the police officer was holding the traffic back to allow enough room for each car to turn around. As I was going backwards, on the second part of my three-point-turn, the car that had been behind me went straight past the officer, who was clearly signalling for it to stop, and then braked sharply. It stopped inches from my offside. However, as I reversed, my offside went into the front bumper of her car and dented my door. Her front bumper only had a small mark. The police officer told her to back up and she went straight into the car behind her. The driver of that car said the damage was minimal and didn't want to pursue the matter. We swapped details and got an incident number from the police officer that was there. I checked to my right before I started reversing and at that point she was waiting in front of the police. As I reversed, I was looking over my left shoulder so I didn't see her move forwards and go past him. My rear dash cam captured most of the incident, so I sent the footage to my insurer. They said I'm liable because as I was reversing I had a higher duty of care than other road users around me. They say I should have been aware of my surroundings. I would appreciate your thoughts.