These laws only work as long as humans also have to abide to laws concerning robots. If it isnt the case, robots are basically just slaves and they even cant defend against humans, if humans attack robots.
That wont matter, if its just a machine, but that would be a huge problem if AI develops a human like consciousness, as its the case here.
In this manga the humans apparently didnt know, that the girl was a robot and that they basically comitted murder, because the robots have to abide to the laws, but Im highly confident, there would be humans out there, who would murder them knowingly-