Any unlawful act or violation of any of the provisions of this chapter on the part of any polygraph examiner or trainee shall not be cause for revocation of the license of any other polygraph examiner for whom the offending examiner or trainee may have been employed, unless it shall appear to the satisfaction of the board that the polygraph examiner-employer has wilfully or negligently aided or abetted the illegal actions or activities of the offending polygraph examiner or trainee.