(a) The provisions of this chapter prohibiting the practice of a health occupation without a District of Columbia license, registration, or certification shall not apply:
(1) To an individual who administers treatment or provides advice in any case of emergency;
(2) To an individual employed in the District by the federal government, while he or she is acting in the official discharge of the duties of employment;
(2A) To an individual engaged in the practice of pharmaceutical detailing for less than 30 consecutive days per calendar year;
(3) To an individual, licensed, registered, or certified to practice a health occupation in a state, who is providing care to an individual, an animal, or group for a limited period of time, or who is called from a state in professional consultation by or on behalf of a specific patient, animal, or client to visit, examine, treat, or provide advice regarding the specific patient, animal, or client in the District, or to give a demonstration of a procedure or clinic in the District; provided, that the individual engages in the provision of care, consultation, demonstration, or clinic in affiliation with a comparable health professional licensed, registered, or certified pursuant to this chapter;
(3A) To an individual retained to testify as an expert witness in any court or administrative proceeding, hearing, or trial;
(4) To a health professional who is authorized to practice a health occupation in any state adjoining the District who treats patients in the District if:
(A) The health professional does not have an office or other regularly appointed place in the District to meet patients;
(B) The health professional registers with the appropriate board and pays the registration fee prescribed by the board prior to practicing in the District; and
(C) The state in which the individual is licensed allows individuals licensed by the District in that particular health profession to practice in that state under the conditions set forth in this section.
(b) Notwithstanding the provisions of subparagraphs (A), (B), and (C) of subsection (a)(4) of this section, a health professional practicing in the District pursuant to subsection (a)(4) of this section shall not see patients, animals, or clients in the office or other place of practice of a District licensee, or otherwise circumvent the provisions of this chapter.