We need to put ourselves back into the absentee child's position, and imagine what they must feel when they are 'invited' to a meeting with the 'Attendance Officer', and a paediatrician psychologist [It has been pointed out that the psychology is a research preference rather than an academic qualification.]. Remember that 'Attendance Officer' is PC-jargon for 'Truant Catcher': Every child who has seen Chitty Chitty Bang Bang, will fear this particular bogeyman as much as they did the evil 'Child Catcher' in that film.
Now look at the scene that Crawley set up, when trawling for new child research subjects: The Truant Catcher and psychologist, have the power to enforce school attendance and to launch prosecutions of parents who do not ensure that their child goes to school. At worst, a child might be removed from the care of its parents and put out to be fostered with strangers. Thus these children and parents are actually being 'made an offer they cannot refuse'. Under these circumstances, many children are going to be terrified out of their minds!
As she is a psychologist, we ought to expect that Crawley is aware of this power game she set up to entrap more research subjects. Even if this was unintended, she has set up a 'Good Cop'/'Bad Cop' dynamic, under which her interviews were conducted. It seems fairly certain that many children and parents would sign themselves up for anything, with every child's bogeyman waiting in the corner to net any child who does not have a 'sick pass' to explain their truant behaviour!
Whether intentional or not: this method of obtaining research subjects to 'prove a hypothesis of undetected levels of CFS among children' is effectively a case of entrapment with menaces.
If we go on to consider that the clinics will be commissioned to 'treat' all these 'newly discovered cases of CFS', then we really do need to look into the commissioning of these clinics, and any 'headage rates' they are paid per child put through their magical brainwashing system. It appears that there may be a perverse incentive to trawl for as many subjects as possible, and with Crawley being judge and jury in her own court, to brand children with her own 'CFS/CBT-ready' mark, for the sake of gains, both financial and in scholarly acclaim.
This looks to be a whole lot more dodgy than merely forgetting to obtain technical approval for 'data gathering'. If I had been one of the children 'invited' to a meeting at school under these circumstances, I think I would have run away from home. (I wonder if they checked to see if any children did run off rather than accept one of these sinister 'invitations'.).