Who would be at fault in this situation?

[JaniceMasters]

I was driving along in the right hand lane and there are signs that say "left lane ends merge right". I was in the right hand lane already and was fine but a truck beside me in the left hand lane (the one that is ending) suddenly speeds up I am assuming to get into the space between me and the car in front of me (this is right after a turn so there is no room at all between me and the car in front of me). When the left lane ends the truck forces his way over almost hitting me (and he would have if I had not stood on my brakes when I saw what he was doing). If he had hit me who would have been at fault? The left lane came to an end and therefore I believe that me, being in the right hand lane which continued, would have had the right of way. However, with the truck suddenly speeding up when he knew his lane was coming to an end puts me behind him so would I have had to yeild to him?