I'm actually a Safety Manager for the company that I work for, so this type of thing is right up my alley...
Where I work, we actually go so far as to approve specific cutting tools for specific tasks, done by specific employees. A non-authorized employee, or one using a non-approved cutting tool (or an approved tool for an unauthorized task) would be setting him/herself up for disciplinary action.
We also require the use of cut-resistant gloves anytime a blade is exposed (during cutting, or while changing dull blades, etc).
Employees are not allowed to bring their own tools from home.
If your friend would have brought a tool like his carving knives to work, he'd be looking at disciplinary action. Had he cut himself with that tool on company time, he'd be looking at even more trouble.
The accident your friend caused will count against his company (it qualifies as an OSHA recordable injury). If your friend feels he's entitled to worker's compensation, he can sue for it. It's very likely he'll lose though, if the company can show that the injury was caused by personal, unauthorized, tools, and that the tools weren't being used for work-related tasks.