[Oyk]

The motorcyclist had the right of way. The car must have made the turn in the absence of a green arrow. If the biker was alert, he could have braked to avoid the collision.  

The MC was riding at a high speed.

The driver turned because he misjudged the timing, and thought that the bike was sufficiently far away for him to turn. 

Even as a pedestrian, many a taim, I crossed small roads which appeared clear of vehicles only to suddenly see a car or bike turning in from another side road. 5 seconds ago, they weren't there. But at the speed they were moving (50kmh?) and the speed I walked, 5 seconds were all it took to turn a safe to cross road into one which had a car coming from behind me.