Yeah, if they had just blocked his mac address then he could reasonably think "hmmm, I can't connect with this mac address, I'll try a different one" instead of "I am no longer authorized". But if you have to keep reconnecting with different IP addresses and mac addresses over and over again, and finally resort to connecting directly to a wiring closet, then the message is pretty clear that you (not just your mac address) are no longer allowed on the network.