To my knowledge that's impossible. It takes 480 days to earn Hero. I'm sure Theymos and admins can set activity levels if they want / need to so maybe some special deal was made for someone serving in a staff role but not called "Staff" or "Admin".
It's hard to tell for sure unless you provide the name.
Well, check this out: https://bitcointalk.org/index.php?topic=1247903.0;topicseen
A newbie called "harryploppers" is selling a Hero account with 540+ activity. THAT is how you do the 'impossible'.
He's using a new account to sell a different account which is hero rank. Its common so they don't risk 'wasting' an established account by people providing negative trust for account selling.
Seems like there's always some who find a way to make some extra scratch. Usually by taking it from someone else that plays by the rules. What a world.