The wording in the media reports make it sound like something out of Asimov where the robot had "turned on his master and grabbed him". The reports then questioned who should be prosecuted, implying that the robot itself could be capable of being prosecuted.
There are effectively two type of robots:
- Moving vehicles, which sense their surroundings and stop if they find anything, like a person, who should not be there, and
- Fixed robots which carry out specific manipulation and similar tasks.
Fixed robots normally have no person sensing devices and must be regarded as being like any other piece of machinery. The thing that makes them dangerous is that their range of reach is normally quite large.
Such devices must be in a protected area (as was the robot on which the accident occurred) and entry into the protected area must be via suitable interlocks or lock-out isolation. It looks like there was no such isolation.
So, let's just forget about the emotive "robot out of control" scenario and remember that ANY machinery can be unsafe and suitable isolation needs to be applied before anyone enters the protected area.