I can only relate what happened to me once.
I was on a roundabout when a moron pulled out onto the roundabout in front of me. I practically t-boned him......well almost. It was totally his fault for not giving way but he claimed it was totally my fault. We both submitted claims to our insurance companies and they tried to settle it between themselves but couldn't.
My insurers asked me if I wanted to proceed further which would mean a court case or accept responsibility and loose my NCB but hey thought I had a good case. Naturally I said 'bring it on'.
They sent an accident investigator (a retired traffic cop) to interview me and survey the scene. He produced a 20 page report with photos an measurements and I was sent a copy to correct any errors. A few weeks later a court date was set and a few weeks after that I was sent a copy of the other drivers court submission and asked for any comments and let my insurers solicitor know.
Well.....The other guy effectively suggested that he'd entered the roundabout in 1st gear and I came round the roundabout at 90mph and should have swerved to avoid him
There was whole raft of inconsistencies in his submission, I listed them all out and then called my insurers and they said they fell about laughing when they read it and called the other guys' insurers and pointed out that it was pointless proceeding to court but they wanted to play hardball and go to court.
To cut a long story short we settled out of court 25% my fault 75% his fault because apparently with a roundabout being involved judges tend declare it 50/50 fault.
I wasn't completely happy but I was relived that it was finally over because from accident to settlement was 8 months
Now the downside, with regards you, is that I had full comp and uninsured loss cover as well which meant none of it cost me a penny. But as Horatio has pointed out already, get yourself checked out by a doctor who is prepared to write up a report on any injuries you may have sustained - some are not always apparent straight away. That will cost money but it will be piece of mind for yourself if nothing else especially if the doc gives you a clean bill of health.