Depends on your equipment:
If he is actually using a receiver, then it makes no sense to use a optical cable or HDMI w/ARC to go directly from the TV to the Speaker as the receiver serves no purpose
A majority of Soundbars have internal amps, so the need for a receiver is not necessary. In that case you can run an optical cable from the TV to the Soundbar at at least eliminate one piece of equipment.
If you want to go a more on the higher end, something like the SuperCinema 3D Array by Golden Ear, then it works differently. The Golden Ear is passive and uses the receivers power for sound. In this case the optical or HDMI w/ARC cable goes directly from the TV to the receiver. Three speakers wires would go into soundbar (FR - Center - FL) from the receiver
Please note that the HDMI w/ARC must be equipped on both the TV and the Receiver. I just started using this with my new LG 47LN5700 TV and Integra 30.5 in my bedroom which is great, because it actually powers on the receiver for me when I turn on the TV.
So, depending on which Soundbar he uses will determine how he connects with the TV. The powered soundbar is the most common.