I have seen on a couple of different shows things that I thought were violations of the National Electrical Code. Both times involved add on electrical outlets and entertainment centers.
IIRC the NEC prohibits using devices (outlets) to pass thru power to other devices. In other words the removal of a device must not remove power to devices downstream from the removed device.
The correct way to do this would be to wire nut the 2 black (or red) connections with a pigtail that goes to the outlet and wire nut the 2 white (neutral) wires to a pigtail that goes to the outlet