You are dealing with NAT or Network Address Translation. His IP address is behind a router's translation layer. For AOL, it could be multiple levels of NAT. The IP that you see on the internet, and the IP that he sees from his workstation are two different things.

I do not know how to configure Remote Desktop to work from behind NAT. Perhaps someone else here can help with that, or maybe a Google on those search terms might reveal a howto page.