I saw this on the TV news last night. It is appalling for all concerned.
I would say there was fault on both sides, but I fully agree with all of those who have said that the speed of the motorcyclist was a massive contributing factor here. I can't prove it obviously, but I can't help feeling that if he hadn't been going so insanely fast then possibly the whole incident may not have occurred. There would have been far more chance of either the car driver or the motorcyclist (or both) seeing each other in time and both would have had more chance to react accordingly. Also, much more chance that they would not have been anywhere near each other.
Nobody deserves anything like this. Yes, I do have a lot of sympathy for the car driver.
To my mind the message should be aimed equally at both car drivers and motorcyclists. Car drivers obviously should "think once, think twice, think bike" and to pause and make sure they have looked as effectively as possible, and motorcyclists should absolutely take on board just how vulnerable they are, and how dangerous it is to ride at such massive speed.
I am sure most of us who drive cars have experienced how startling it is when suddenly a motorbike appears from behind out of apparently nowhere and comes flying past. It can literally happen that quickly.