I don’t think there’s any certain info about how this works, but since Uber accounts are linked to the driver’s personal ID, I don’t imagine there are many drivers willing to go on a crime spree where their identity is known.

That being said, the most likely explanation is a driver getting their phone stolen, or getting their login info stolen. In that case, you’d be able to detect that something was “off” if the car or license plate don’t match the app info.