Originally Posted by iPilot

They might not of been flying around but while they were operating the gates at the airport they also fall under the rules of an air carrier. The fact that they accepted the flight and then told them no when they got on the ground is where the problem lies. If they had already closed up shop for the night or even said no from the start then they wouldn't of been liable. However, when they said they would service the flight they then became accountable for unloading the passengers into the terminal as promised.