I doubt that actually. Done right the bandwidth used should be less than in a client-server model. The idea is that the peers talk to each other directly and the data does not have to go all the way to the server and back. But I guess I was trying to say that he is not stating the real reason behind the decision.
Also, in a corporate setting, if you make a call to a buddy in your building, chances are the data will be routed on your own private routers and never even hit the ISP. I'd say that was a big plus for P2P.