Minor car collision, need urgent advice

A car seemed to hit into the back of my car as I was setting off. At the giveaway the car behind me was nudging forward as I was stood still, then as I began to pull forward my car crept back slightly as both cars made slight contact. Both myself and the other driver got out of our cars to inspect what had happened. The cars were touching each other however when the other driver moved his car back there appeared to be no damage, no scratches or dents.

He claimed to be in a rush to work and noted down my number and address before taking a picture an leaving. He mentioned that he'd ring me over the weekend but I haven't heard anything back. I'm not interested in making a claim, however I just found out that it would be in my best interest to mention the incident to you in case the other party tried to make a claim etc.

I didn't take down any details regarding a contact number, address or vehicle details as I knew that my car was not damaged, and was told by the other driver that he would contact me. My question is do I contact my insurance company, or do I just wait it out. I don't want to loose my no claims bonus as I've not even completed 1 year of driving, however I don't want him to exaggerate a claim and then blame be put on me for not having reported this.