The board may revoke any certificate issued under the provisions of this chapter if the holder is guilty of:
1. Commission of an offense determined by the board to have a direct bearing upon the holder's ability to serve the public as a plumber, or the board determines, following conviction of any offense, that the holder is not sufficiently rehabilitated under section 12.1-33-02.1;
2. Error or fraud in obtaining the holder's certificate;
3. Permitting the use of the holder's certificate and license in violation of this chapter;
4. Incompetency;
5. Failure to furnish certification of completion of continuing education as required under section 43-18-17.1; or 6. Failure to report work as required under section 43-18-17.2.