I mean, if there are any humans at all in the environment or even nearby, I think it is. A robot which thinks it's cool to throw a bag of tools or whatever is, sooner or later, going to screw up, because it will be impacted by a factor it hadn't accounted for (maybe the board it's standing on is improperly mounted and slips whilst it's throwing, or it has a joint freeze for a 1/4 second during throwing motion) and suddenly some human foreman or maybe even just someone walking by the worksite is being hit by a bag of dense metal tools falling from 20ft up.