I assume autopilot would always drive according to rules (I doubt they would get licensed otherwise), so if pedestrians pop up in front of a car, I it's likely their fault.
I do find it hard to imagine a situation where the auto pilot has to choose one life over another -- I've never had to choose that and I've been driving 20+ years...
Someone runs out into the street, likely the car can brake or swerve. I've stopped for my share of kids chasing soccer balls without so much as a spilled latte.
Deer, moose, cattle on the road maybe it's different... The car will have to determine where to place the impact. But hopefully cars with more censors avoid these things better than people do. We are pretty bad at spotting deer...