Insurance situation unclear Car rental accident

Hello everyone, some time ago something stupid happened to me and a friend. We or I had rented a rental car at SiXt and was on the road with it. I am 18 got my driver’s license all right. My friend was 17 at the time with his B17 driver’s license. During the ride I got uncomfortable, I got dizzy and I drove right. My buddy offered me to drive home after it was not better. (We were not 3km away from home. ) On the ride what had to happen, he took a traffic island with him. Fortunately only a metal damage but the problem was that the police was already on site before we could get out of the car. So of course my buddy had driven. He had a stupid situation without a valid driver’s license of course. We told the police everything and they said it would be a clear case “driving without a valid driver’s license” -> My problem is now I get from SiXt b The insurance company and the police stress because I let him drive? He was not in the rental contract as a driver (we also without 18 driver’s license). Thanks already to all who accept my question Clemens