That guy can defend you in almost any state. He is either on the Bar in more then one state, or he gets local concil and becomes part of their legal team. The legal term for this is pro hac vice.
: (proh hock vee-chay) prep. Latin for "this time only," the phrase refers to the application of an out-of-state lawyer to appear in court for a particular trial, even though he/she is not licensed to practice in the state where the trial is being held. The application is usually granted, but sometimes the court requires association with a local attorney.