Why play their game then if it can only end up looking bad for you? Suppose Kate really struggled with the kids, suppose they were bad sleepers, suppose she had often been at her wit's end - suppose she admitted all this to the police? She has handed them motive on a plate, even if this lack of ability to cope had nothing whatsoever to do with MAdeleine's disappearance.
IMO that is exactly what they were trying to do i.e. prove that Kate had not bonded with Madeleine and didn't care about her - in fact she was more of a nuisance to her than anything else. Didn't they do a similar job on Leanora Cipriano?
The fact that they treated newspaper tittle tattle, gossip and rumour as serious evidence on which to base questions is what I found to be so jaw-dropping.
The question - ''What does 'We let her down' mean'' was positively cringeworthy IMO - when all they had to do was ask one of the UK police officers who had been working alongside them for months on end.
If that and other questions was a mark of their professionalism then it left a lot to be desired IMO. But then what can you expect from policemen who claimed that it was a dream which changed the whole direction of this case.
The best decision Kate ever made IMO was to claim her right as an arguido not to reply.
AIMHO