If it is a single McD employee, fine said restaurant (which is already the case, but you onow that don't you?). If it is a general issue with a franchise chain (McD is running a franchise, so the company to go bankrupt is most likely a franchise in your example), fine them. And yes, that can lead to bankruptcy, as happened a couple of years ago with a Burger King franchise chain in Munich.

If McD is knowlingly selling carcinogenic burgers world wide and reguses to stop, sure, bankcrupt McD.