Of course you should worry. The attacker may have sold the cert to other parties...

marshray on Aug 29, 2011 | parent | context | favorite | on: Gmail.com being MITM'd by Iran using this certific...

Of course you should worry. The attacker may have sold the cert to other parties, not just Iran. Or if it was Iran directly, they may sell the certs to other parties to make a pretense of deniability.