Agreed, from the letter of the law (& insurance determination) the MC was basically 100% at fault for turning into a lane that wasn't clear, but.... the light turned with MORE than enough time for the car to stop before it went red, but the car made zero effort to slow down or stop - the light would have likely turned read on him while he was in the intersection even without the collision which would have placed some of the fault on the car.
Either way, stupid move on behalf of the MC - never just assume or trust that crossing traffic in this situation is going to stop - I *always* assume cross traffic is either going to not stop, or turn.