If i'm not wrong, under contract law, toastbox have an "implied
responsibility" on the customer to serve reasonably safe food. So
even if the nasi lemak is not prepared by them, but by some
outsourced supplier, toastbox too have a share of
responsibility.
I think if in US, sure go court...
The way the staff handled could be improved. I tink sg's problem
with rude retailers is that the staff dun feel for the customers,
hence creating an even bigger problem. But I am surprise the staff
did not notify the supervisor, whom should had come out personally
to offer refunds and apologises on behalf of toastbox.