I like the idea of calling the hotel and offering to pay for it, or return it. It's very true what you say about children getting themselves in situations that they don't know how to handle (like Kirby coming home with the $20). That's why I feel like my response to this situation is important because it could determine how other, more difficult situations will be handled in the past.
I'm off to look up the phone number of the hotel!
Molly in Ecuador