That is *so* not what really happened!
Follow the links to the New Scientist article: the whole thing was a designed experiment to test human pain thresholds: "But the robo-battering is all in a good cause, insists Borut Povše, who has ethical approval for the work from the University of Ljubljana, where he conducted the research. He has persuaded six male colleagues to let a powerful industrial robot repeatedly strike them on the arm, to assess human-robot pain thresholds."