Yes train him as you would any new driver. Why would anyone go to an individual that charges $150.00 an hour is beyond any sensible reasoning I could come up with.
Train him as you would normally train others. Do it your way to ensure that he receives all the information properly, and effectively. Handle it as if he was never trained before, as it seems like he wasn't for his $600.00.
There are no ethics. The government can't kick out any trainer, or organization for poor training. If they, the operator, falters, and the government can prove that it was due to the lack of proper training on behalf of the trainer, then the trainer can be held accountable.
If this operator was involved in an incident, and the government and or lawyers could prove that he was deemed competent ineffectively, then this guy is out of business. But these scrupulous trainers seem to hang around like a bad smell with impunity, while we dedicated professionals seem to pick up the pieces.
Get this person in a classroom, and start all over. That is the only thing that can be done.
$600.00 for a morning session. Talk about being taken for a ride!