The line may be exposed in the living room and the contract said it would be but the lines location prevents the vent cover from being replaced in the hole in the duct. So besides the lines there is a gaping hole in the duct and probably no room to build a box around them.
They have left the soft copper lines exposed in the furnace room so that anyone who has to work under this duct or get to the other side to access: the water lines to shut off or turn on the water to the humidifier, get to the items on the shelves on the right in the picture, access the hot water heater which is due to be replaced as it is 14 years old, or clean the air cleaner which is directly below the duct and refrigerant lines is likely to hit their head on the duct and refrigerant lines because the distance to the floor was less than 5 ft under the duct before they installed those refrigerant lines.
The electrical box outside that they installed for the service shutoff is not locked and the inner plate falls to the ground when the lid is lifted. There is no screw or lock of any kind to hold this inner plate in place. There is nothing to keep a child or my 3 year grandchild from touching the wire connections. The cover plate that is supposed to be over the wires falls to the ground when the lid is lifted. There is a swimming pool within 10 feet of this box as well and children swim in the pool.
Personally I think this is shoddy work and it was done with this lack of care because I am disabled and was not able to inspect their work or watch what they were doing and they knew it.