Your insurance agent doesn't decide whether or not the state will determine you to be at fault for an accident. You won't be able to sue the state for this, even if it is assumed that their assessment is unreasonable, due to governmental immunity. Also, as you should know the capacities of your car, didn't observe traffic lanes, and intentionally drove over the obstacle which damaged your car, it isn't immediately apparent that the state's determination was unreasonable.

