Just Invading private space ....
The car is merely invading the pedestrian's private space to liberate it from its miserable life (which it must be because otherwise the pedestrian would drive a Mercedes).
The pedestrian doesn't like that invasion and to protect himself throws the arms in the air. The car interprets this as a terrorist act and the pedestrian insurgent is quickly run over and killed - legally.
Killing of the pedestrian is merely collateral damage.
The car then declares "mission accomplished", goes in reverse - before leaving other pedestrian to clean up the mess on the sidewalk.
See it all makes sense when you look at it this way.