Car accident... we were turning left and the semi sped up to make it through the light, who was at fault?

We stopped at the light, we were headed left, there was plenty of time for us to make the turn. A semi in the far lane sped up because the light turned yellow. We had almost made it when he slammed into the right side of our van. The officer didnt find anyone at fault because he only questioned 2 witnesses (there were more). One witness stated we ran a red light and the other stated the semi did. (noone ran a red light, ours was green and his was yellow). Our van was totaled and we didnt have full coverage. He lost a piece of his bumper. Is there any chance of his insurance paying for the damages even though the officer didnt find him at fault? Should we get an attorney?