My first thought was 'with that much damage, there should have been a police report,' which you confirmed. I don't know much about such reports in general or your state's procedures in particular, but I'd expect there to be more information identifying the vehicles involved than just the license plates, such as the VINs. On a related note, quite aside from the fact that the insurance company is claiming that an official state document is wrong -- something not likely to endear them to the officials who create and maintain such documents -- there's the fact that a lot of companies that operate semis keep real-time GPS records of their actual location, and there's a big difference between a) 'our records say it should have been over there' and b) 'our records say it was over there.'

My second thought was 'what has your insurance company said about the matter?' I haven't had to file a claim since moving, but every State Farm office I've dealt with in the past has been willing to go to bat for me in a dispute. I don't think it ever had anything to do with what kind of insurance I had (aside from the carrier, obviously), although I could be wrong. IMO, it's more likely to be a question of how long I have stayed with the same carrier.

I'm pleased to see that I'm not the only person who had these thoughts. I wish for you success in your struggle.

<sits back down, muttering unpleasantly about a company that seems to be defending inappropriate behavior in order to save a buck>