Usually in accidents involving a left hand turn in an intersection it is the one who was making the turns fault. You must realize that he switched lanes while in the intersection, which is illegal. He was supposed to turn into the left lane (lane closest to him) Therefore, since he made a poorly timed turn (first fault) and proceeded to cut you off by changing lanes (second fault) I would have to say that he would be at fault. However, insurance ocmpanies can screw you over at times and say that you were proceeding at an unsafe speed and rear ended him. That when there are alot of gray area that come into play. Do you have any witnesses or was there a police report made?