If someone fires a gun randomly down the street, not aiming at anyone, but happens to hit someone, they'd certainly be arrested. Drive a multi-thousand-pound projectile down the street, kill someone, and it's just an "accident". The default needs to move to charging every driver involved in a fatal crash with manslaughter. Currently the police won't even perform basic investigative work that would make any charge pos…
One time I was riding my bike when nearly the exact same thing happened to me as this woman, only instead of a small child the person was an older man. He, looking for traffic the wrong way on a one-way street, mistakenly thought it was safe to run across the road. I was doing the speed limit (60kph) when I hit him, full force, and sent him tumbling down the hill about 15 feet.
It wasn't my fault at all, but that guy was totally wrecked. I was a bit sore, but overall I was fine. Him on the other hand - his body helped break my bike frame (bent one tube, snapped another right from its welds, broke my wheel, ripped cables free), he had nothing to protect his head, and he looked frail to begin with. It was bad.
Should I have been charged for that? I don't think so. He did it far too suddenly for me to do much more than hit my brakes. I felt awful about it, but I definitely don't feel responsible for it.
If I'd been going the wrong way, he was at a cross walk, or something - something where I should have been more prepared to stop or avoid him - then absolutely. But sometimes pedestrians make really bad calls and road users just aren't at fault.