Your friend can retrieve his account by sending a PM unto Cyrus or theymos with a signed messaged on one of the addresses used on that account.
But currently theymos and Cyrus rarely retrieve hacked account so your friend may expect for his account for 1week or maybe 1 month or more.
Regarding about retrieving account via Email, I heard things that it might get the account banned since that's broken.
Anyway I found one address that has been connected to his account via bctaccountpricer site.
Found 1 addresses
1LDByWNVDMyQuvY3Di9sHiyxCyRUexPe28