I think the issue is that it can be difficult to prove/disprove intent for something like stolen lunches unless there was a camera pointed at the fridge (or some other clear indicator) if you're going to fire someone over it and be protected against a wrongful termination suit.

It's a bit over the top to have that in place to enforce the policy unless it was a known issue in that workplace. So the statement the GP made seems a bit extreme without context.