I wonder: what would the pilot do if (having agreed he is P1) the instructor tried to take control, he could just turn round and say: 'I'm P1, so get off the controls!' Instructors agreeing to be a passenger on a check flight do so at their peril
Sounds like attempted hijacking to me, if a passenger tries to takeover.
Dial in XXXX to the transponder and call for fighter escort and then encourage the CPS to put the guy away for a long time
