#16 ” Did the trainer maintain an appropriate non-discriminatory manner”?

Ok, let’s start with what the ADI1 (Guidance for examiners, marking ADI part 3 or SC).
The document states, the PDI/ ADI should maintain an atmosphere in which the pupil feels comfortable to express their opinions. They should an open, friendly environment for learning, regardless of the pupil’s age, gender, sexual orientation, ethnic background, religion, physical abilities or other relevant factor. This implies active respect for the pupil, their values and what constitutes appropriate behaviour in their culture. This explains this sub-competency quite well.
Also be careful not to touch your pupil as well, this should only happen accidentally if dual steering or reaching over to cancel direction signals.
Also be careful how you pass comment on other road users, like saying, “bloody taxi drivers” and stereotyping other types of vehicles, as your pupil is listening to this and can form future opinions and decisions on what you say. They should understand why other road users perform certain actions and understand to accept it’s going to happen, but to ready for it and react, without passing judgement.