It comes down to what the witness and the driver of the car say. I was in a similar accident many years ago, when someone ran a stop sign and turned in front of me cutting across 4 lanes (all in same direction). I ended up on the ground to avoid collision, had no contact with the car, and the driver was found 100% at fault. No one expects you to stay on the bike when something like this happens, when the bike falls it could go in any direction. Whether it makes contact with the car or not it makes no difference, as long as the witnesses can explain exactly what happened.
OP's problem is the car got away, so this would be similar to a hit and run scenario, you better have great witnesses that can explain it wasn't your fault...