A supervising lawyer under whose supervision a legal intern or extern does any of the things permitted by §§ 16-18-2.4 to 16-18-2.7, inclusive, must be a lawyer authorized to practice law in this state, and:
(1) Must be a member of the South Dakota bar, in good standing, and shall certify such in writing; and
(2) Shall assume personal professional responsibility for the conduct of the legal intern or extern.