conflict of interest

Company XX  will be supervising the quality of AA work on behalf of client YY and at the same time ZZ (which was promoted by XX and where common directors also present) training the employees of  AA  and taking payment from them:

-          Can YY (client) claims there is conflict of interest in XX  certifying the work of AA  while ZZ (XX’s other concern) only trains them as well?  Please Clarfy