Pedestrians "assuming" certain things (aka acting irresponsibly) is the worst.
I often see people cross the street halfway to only stop at the last second when a car is about to pass them. For people driving at 50km/h this is terrifying because they have to trust that the pedestrian is fully aware of his dangerous position. If you maintain your speed there is a good almost 100% chance that you will pass the pedestrian before he even reaches your lane but if you slow down then there is a non zero risk that the pedestrian didn't see you and you are about to run him over. So nope, defensive driving is not the answer and can actually increase accident risk in this specific scenario. It was all up to the pedestrians to follow safety basic rules and they broke them to cross the street a few seconds faster.
The car is also assuming how the pedestrian will walk, I'm pretty sure we're just describing an adversarial game here. If the pedestrian guesses wrong they might be hit by the car, if the car guesses wrong the pedestrian might be hit. This means you can have easy rules that look clear cut, but in practice the risk for both parties makes me a pretty defensive pedestrian and driver.
You drivers are the ones who stole massive amounts of prime land from the commons for your cars, and now you want us to adjust our behavior to make driving easier for you too?
I often see people cross the street halfway to only stop at the last second when a car is about to pass them. For people driving at 50km/h this is terrifying because they have to trust that the pedestrian is fully aware of his dangerous position. If you maintain your speed there is a good almost 100% chance that you will pass the pedestrian before he even reaches your lane but if you slow down then there is a non zero risk that the pedestrian didn't see you and you are about to run him over. So nope, defensive driving is not the answer and can actually increase accident risk in this specific scenario. It was all up to the pedestrians to follow safety basic rules and they broke them to cross the street a few seconds faster.