Well if the front of his car is damaged and the back of yours is damaged the I'd say he doesn't have a leg to stand on either!
I hope you told the insurance company that he admitted liability at the time of the accident by saying sorry!
Might be he was in a company vehicle and is trying to dodge the blame if he's in bother at work over it?
If you gave a clear map of the incident when you filled in your claim form it should be clear. I mean, who swerves round someone then cuts back in... to do the damage you describe you'd have had to actually reverse into him.
I know its stressful at the moment but the insurance companies are usedto dealing with people like him, you pay them to sort crap like this out for you. Do agree with trying to see if any cctv footage is available, can you get someone to drive you back to the scene to see if you can see any cameras, and what they are attached to (ie lamppost etc), that might give you a starting point to see who to contact.
Bear in mind though that often they don't even keep the cctv footage for more than 12 or 24 hours. We were involved in a terrifying near miss a few years back when a woman pulled out of standing traffic on the exit slip road, right in front of dp doing 60mph. He braked sharply and somehow we drifted across onto the hard shoulder, through the gap she had left by pulling out. It was horrible I was shaken for days. We carried on and caught up with her, got her reg no, and I rang the police the next day.
The officer was very understanding and took her number, said he would send some one round to have a word with her about reckless action, and agreed that we were very very lucky indeed not to have hit anything else - at 60 it would have been horrific.
However (there is a point to all this!) unless there is actually an accident which needs evidence from the cameras, the footage is on a constant loop and overwrites itself after 12 hours or so. They simply can't store all that footage from potentially thousands of cameras, for days or weeks, so be prepared for the footage to be wiped already.