Nightmare diversion today down narrow country lanes in back-to-back traffic. I had to do a very tricky manoeuvre, passing millimetres from another car's wing mirror (with that driver kindly helping me inch along) and offside wheel at dodgy angle on a sheer verge. There's an extremely small possibility that as I was inching along, I rolled back into the bumper of the car behind me (gas/clutch control, bit of kangarooing while making small adjustments at sub 5mph). As we passed the obstruction, still driving down single track road, the car behind tooted a few times. Not sure if he was heckling my driving or if I'd actually bumped his car. Indicated and pulled in at first safe stopping point (main road with free flowing traffic). Expected him to pull over too. No damage to my car. He seemed to stop, saw my husband and I get out of car, then drove off. Obviously if I did damage his car, totally fair enough, happy to exchange details. But impossible to know as he didn't stop. Do I need to flag this incident to my insurance, in case they decide to claim? Or wait to be contacted in the event of a claim? As I say, no damage to my car, if impact was made it was at v low speed, and they didn't stop to talk to me when I pulled over?