On the way driving to a fireworks display a few weeks ago in the car, lots of traffic crawling through Hammersmith and a firework goes off close to the street (must have been a nearby back garden), large rangerover stopped abruptly in front of me (slow moving traffic), and I stop sharp (we were literally crawling through Hammersmith - could not have been going faster than 5 miles per hour because I was travelling a few feet every time we could move forward) and our bumpers meet (well not quite because rangerover's bumper is that much higher).
Driver in front stops, gets out in the middle of the road traffic and I wind my window down and indicate that we should pull over and exchange details which we do. In exchanging details I mentioned the firework making everyone jump (I thought that was why the driver had stopped sharp) and realised the driver was deaf (I wasn't too quick on the uptake because of general noisiness and not sure its relevant apart from as to whether the firework was why she stopped) and we swapped numbers and I took photos (not great quality on phone) of a few faint silver/white marks on the bumper but when I touched them they actually rubbed off (which I showed to the driver) and could feel that the 'scratches' were not actual grooves but paint marks.
Have now received notice of an insurance claim! Is the other driver legally obliged to put in a claim or are they trying it on? Also is it automatically my fault if you bump the back of someone even if they stop abruptly (possibly due to firework)?