An instructor is not a passenger in the circumstances given!
Except where his or her presence is not required legally by the ANO.
There is an anomally here.
If I checked someone out for an hour or so and then said at the end of the flight. "I am sorry but you handling of the aircraft was not good enough to me to allow you to fly the aircraft solo How would they then log that flight, P1 or Pu/t?