Crazy Driver Rear-Ends Biker at High Speed [Video]
In this particular case, the higher speed of the motorcycle could have meant a lesser impact with the car approaching from behind. However, given the fact that the rider did not remain upright, and would most likely come off the bike even after a slightly less violent impact, hitting the ground at a greater speed does not seem the best solution.
Unfortunately, this is a case of extreme bad luck for the rider and I can't really see any way he could have avoided the crash. The speeding car from behind bears all the responsibility for this nasty crash, and I can only hope the police got the guy and nailed him really good.