This user have 2 accounts: there and on Stack Overflow. Both of them haven't reached 200 reps yet. If not bonus, they both were at 1 rep. But he has association bonus.
Then look at it. (May 30) (per Shadow Wizard)
Well, they received the account association bonus here on November 4, 2013. Considering that their Stack Overflow account is only even 3 days old, the only logical conclusion is that they once had an account with enough reputation which has since been deleted* (since you require at least two accounts for the association bonus to even kick in). Note that once you've gained the association bonus on any network account, you keep it forever and it continues applying to all future accounts even if none of your current accounts qualify anymore.
* Note that as a moderator on Stack Overflow I can confirm that this is very likely the case, but cannot reveal more detail than that.