Was he using balanced connections? This only applies to balanced audio schemes...and ground the out and float the in is the industry standard.

As it a applies to unbalanced connections? I don't think your going to see much difference with using that method. Normally you would just use the shield connection and one conductor. If your running unbalanced cables long distances, use a twisted config with foil and drain. Canare makes some great cables that are inherantly resistant to RFI.

Unbalanced cables use the shield as a ground return...