Well, we can know for a fact this not Namielus or Cerberus; Mr. H is far to coherent.
I didn't see Hamilton myself today, so I'm not sure if this could be him... To my knowledge, however, none of the teachers at my high school are aware of the CPA, at least not in relation to me. Hamilton _does_ see Duel everyday, so I wouldn't be too suprised if Duel told him about the CPA.
However, I also have to point out Hamilton's commonly referred to memory- or lack thereof. I doubt he'd remember both the URL for the CPA, the spelling of my username, AND that I have 'super-duper admin' powers.
It's possible, though.
If this is Hamilton, good to c'ya! If it ain't, I'll hunt you down and get you nailed for impersonation. I'm not gonna lay bets either way, though!