Interestingly it neatly ducks the issue of whether a passenger may operate the controls.
9.6 Can the passenger operate the controls of the aircraft?
An introductory flight does not count towards the grant or issuance of a licence. If someone wishes to have a go at flying the aircraft they are advised to arrange a flying lesson at a Registered Training Facility or Approved Training Organisation.
Note: This paragraph only applies to 'Introductory Flights', not to 'Cost Sharing" flights
In this instance I wish the CAA had used its prerogative to unequivocally ban the possibility.
I see nothing wrong with a passenger flying with a 'friend' being allowed to 'have a go' at the controls - irrespective of whether the cost of the flight was shared or not.
However, an unknown member of the public who has arranged/booked, and is paying for, an 'Introductory Flight' has no business asking for, or being offered, the chance to control the aircraft just because they happen to be sitting in a seat from which the controls are accessible.
They have booked and paid for an introduction to flight in a light aircraft. If they wanted an introduction to flying a light aircraft then they should have booked and paid for a Introductory Flying Lesson.