The thing about TOR is that two people can have the same IP especially when there is network congestion. I've had times where Vidalia assigned me the same IP on two different computers. Not only that but I've also had times where I have to switch my identity 10 times just to get a new IP.
While I fully understand what you're saying it has nothing to do with this. AK claimed to have been running an exit node.
Because you can be using the same IP address as an exit node. Hence TorBlock etc..