There is fault on both sides here.
She was crossing the road and I can only assume that she didn't look properly before stepping out. He was riding a bike that had no place on the highway. Yes it was an accident, it could POSSIBLY have been avoided if he had a brake.
The telling thing for me though is his general attitude that has no responsibility and that he was fully in control - I do not see how you can ride on a public road, with traffic lights, crossings, drivers etc and be FULLY in control when you have no means of bringing your vehicle to a halt in a timely and effective manner. The independent testing has also shown that he would have stopped in 1/3 of the distance if he had a brake. That doesn't allow for reaction time but given that he had the time to call out to her there was time enough to start slowing down, reducing the collision speed and possibly saving the woman's life.
Maybe it will at least be a wake up call to pedestrians who are on their phones when crossing (as it is alleged she was) and to those who have jumped on this Fixie craze thinking it is cool/hip etc.