After parking in a shop's car park, in the only slot available, I saw someone on his phone. I ignored him until he came up to me aggressively and accused me of bumping into his car. I told him I had not done so. My sister and brother-in-law, who were in the car too, confirmed I had not touched the other car. The man proceeded to bully me, claiming he had friends in the police. He would get my address and send some men round to my door to sort me out. He repeated that I had damaged his car and pointed to a vertical scratch below his door handle. I said it was impossible for me to have created a vertical scratch. He said he was going to call the police. I said fine, but he didn't call them. Unfortunately, my phone had run out of charge so I was unable to call the police myself. After some minutes of silence, I left the scene as the man continued to threaten me, despite my having done no damage to his car. In my view he was hoping to scam money from me. Some months later, he contacted his insurance company about it. I told them there was no case to answer, but he has continued to press his case. My insurance company have said they will probably go ahead and pay the claim he has made as he has now shown another scratch - not shown at the time - which indicated the truth of his case. I do not want to lose my no claims bonus to some bullying scamster. What can I do?