As I said the refrigerator in the shop was full.
I understood that.
My point is that if you have a refrigerator in an area designated for customers, along with snacks and drinks for said customers, I could easily see a customer assuming anything in said refrigerator was fair game.
I'm thinking of one shop where a friend works, where they have all sorts of snacks, drinks, and other food items, some in a refrigerator, for their customers.
How you or the employee who lost their lunch proceeds, is up to you.
You can call out the customer:
Maybe they'll only be embarrassed when informed of their possibly honest mistake, and will insist on making things right with the employee.
Maybe they'll be offended by being accused of stealing, when they thought they were just eating something they thought was offered, and will cost the business customers by posting on social media how they were treated by the business.
Maybe the shop tacks on the cost of the lunch to the bill. Doesn't say anything, and employees go forward knowing the risk of placing items in a refrigerator in the customer waiting area.
When I was a business owner, I would've given the customer the benefit of the doubt, and not said anything to the customer. I also would let employees know of the potential risk of losing their lunch if placed in a refrigerator in the customer waiting area.
If I were an employee, I'd likely not take something to work that required refrigeration, knowing of the potential issues of doing so.