It depends. From an OHS liability perspective, the employer, supervisor and worker himself could all face potential charges depending on what happened. Key questions: Were any OHS violations committed’ If so, did the defendants show due diligence, which would all depend on what happened and whether it was foreseeable. In terms of your own risk management, your awareness of the pattern of workers walking off site puts you on notice of the problem and requires you to take reasonable steps to address it.
As for workers comp, I just can’t answer without knowing exactly what happened, where it happened, who got injured, etc.
Sorry to be so general and vague but these are extremely broad questions. Feel free to follow up with me directly if you want to discuss in greater detail. glennd@bongarde.com