Just because someone is an alcoholic and has 12 months sober and wishes you to sponsor them, whilst he works the Steps, correctly with you, doesn’t mean he has scruples, at that pre-step stage. I understand that you trusted him, but nobody signs a confidentiality agreement in AA. Certain peoples’ conscience agrees to anonymity.
I don’t mean this as harsh as it sounds, Paul. But if you value your anonymity so highly, why did you invite this sponsee into your professional/personal office? Knowing the potential that such information would be placed out there, in the ether? We are all fallible.