k in the seoson finaly when meridith is with jhon doe AKA george whats with the 007 thing

In season one, episode one, Georgie was the first intern to scrub in a surgery, with Burke. During the appendectomy procedure, George almost killed the patient (in short, he was doing well but he froze) so after that everyone called 007, which means licence to kill! That's why Meredith knew it was George after John Doe wrote 007 on her hand!