For all of you that have said "yep, nothing wrong here, they ate, they pay", well, ever heard of such a thing called Diplomacy? Or some ethics? Mention to the friend to have the bill payed later if it's such a huuuuuge loss to the crappy little Chinese shack that $30 bucks is gonna break the bank and make them go assup!
Patheitic really! The manager should be sacked and the bill could well have been issued at a later, more appropriate time!
Bad, bad customer service!!!