Have to agree, if you trust a trainer enough to put a dog with him then let him do his job if he wasn`t up to scratch then he wouldn`t be making a living from it , it`s good for owners to take an interest and even discuss things with their trainer but at the end of the day the trainer should be left to make the decisions on dogs in his care,
and if you think the trainer is not up to scratch and needs your advice don`t put your dog with him, simple