Well, it's still the person in the moving car's fault for hitting a stationary car, even if it was parked illegally. Just like if you came around a blind corner and hit a car up the rear that was legally parked though you didn't see it till too late.
It would be more complicated if the moving car had knocked over a child crossing the road by the school, and the driver said that their view of the child was obstructed by the illegally parked car. That actually might help the defence of the driver, I would have thought (assuming their view really was impaired by the parked car).
I didn't know it was 3 points for parking there either. But that's pretty sensible, and it really needs enforcing.