H500 but you did not "Show" him stuck pedals did you! You tested him in that exercise unbriefed having originally briefed a VOR procedure.
I am sorry but even 10,000 hour ATPL in full time employment need retraining on many exercises prior to the check. This is precisely the reason for the 6 month OPC and the training mandated prior to doing it. These requirements are a clear recognition that in 6 months of normal flying, skills fade on those exercises that cannot be done without an Instructor.
Your 400 hour PPL has my sympathy. The poor guy was struggling generally as you describe so just to heap sh1t on him you do the unbriefed TR procedure.
Mate I would take a long hard look at your conduct with this guy and ask yourself, did you help him at all and I a, assuming the poor sod paid for this humiliation.
No bud I will fly with HC long before I put myself in your hands.