Can a restaurant owner demand that a server pay for the bill that a customer has "walked out" on?

Are there any laws specific to this situation? Do they vary by state? The state in question is Vermont. A woman "loved her meal", left a generous tip for the server, but forgot (?) to pay the check. The server was VERY attentive, and in my opinion should not be responsible for the loss. Can a restaurant owner demand their employees pay for the check?