Jerbil
Sounds like you have a problem CT, we have been through a number of those, the worst of which we eventually reported to the NSPCC.
The issues the CT is limiting her comments and attitudes based on behavior, which is the limit of many in the education systems training and professional understanding of all classroom issues, which then means that all problems and failures are responsibility of the child or the childs parents, and nothing to do with the teachers lack of training, qualifications, or the responsibility of the school. This is a hangover from the 1980s when all education was see as a behavior issue, and not about the various cognitive or neurological issues which can create learning barriers which teachers now need to fully understand to enable them to provide the teaching methods best suited to each childs needs. The majority of children are able to access the full range of learning abilities required for each task they need to learn to perform, bur many others require information and teaching to provided in methods and ways that their specific learning abilities are able to processing and understand. So your CT would appear to be a below standard teacher, who lack the required knowledge and understanding to be a primary school teacher, and unfortunately there are many of them about.
It also sounds as if the school are not very receptive to outside support, and advice, again we had similar issues some years back, and eventually nearly all the staff moved on after the dominating poor quality HT left.
Unfortunately dyslexia is a man made problem, not a condition, but you seem to have identified one of the underlying cognitive causes of the dyslexic symptom, his visual processing problems, which is a medical issue, and a disability which the school if properly run should take note of and provide the the correct support under the Disability Equality Duty (DED) requirements of the 20005 Disability Discrimination Act. Each school has had to have a DED policy in place since 2009.
Those who have any of the various cognitive deficits are able to develop and use coping strategies for a limited time each day. Running these coping strategies is energy consuming and stressful, so we can run these coping strategies and seem as normal as we can be for a limited time, say at school, but we need some form of release when it is safe to be ourselves at home etc. The same applies to adults when at work, and needing to let go when at home and hopefully those at home have some understanding of our needs to allow us to let out the built up stress, can drive my DW to the edge sometimes, as as we both share the same disability, we have some understanding of each others coping mechanisms.
Sorry to have rambled on a bit, and probably off topic.