Was Craig Owens a true companion? We think yes. And no, we won't hold it against him that he is so easily swayed by the Doctor's omelets — or the fact that he uses the word "geronimo."
Craig was a worthy temporary sidekick in the multiple episodes we saw him in. How could we not include the infamous Gallifreyan Mind Meld, in which the Eleventh Doctor tries to knock some sense into his unwilling human flatmate?