Uhhh -- The wording is "for a period of at least five years", not just at some time during the five year period.
According to California Code, when an attorney is on inactive status, they are still "a member." The issue is around the phrase "admitted to practice before the Supreme Court of the state for a period of at least five years immediately preceding his election."
Under Brown's interpretation, someone graduating law school and passing the bar in 2000, then immediately going "inactive", never practicing law, could still be eligible to run for Attorney General. That makes no sense to me.