Claw
I fully agree with you re 'proving people to be incompetent, is they lie, no matter how far up the chain you go!', but the alternative is to allow the information to stop at head level, ie the governors are unlikely to be aware at all.
One of my big mistakes, I feel, was not going sooner to the governors. Instead I let everything build up, by the time I put my complaint in it had got too big to manage. While the GB came down on the side of the school, I do believe I managed to discredit the head somewhat.
At the moment your complaint is manageable and you can break it down.
School have no evidence of attainment/progression for SALT, motor/social skills group - linked to Aims and Ethos Policy. Curriculum Policy if they have one.
Lack of IEP's, progression mapping etc linked to SEN Cop, Schools SEN policy, also Aims and Ethos Policy.
If your school told the tribunal they have this info then the GB should ensure the school actually have this, or look into why they say one thing then do another.
Your school are now saying Tribunal made a mistake, did they attempt to rectify this with the Tribunal at the time?
If you don't have them get hold of your schools policies, always try and link your complaints to their policies. This will also help give you additional evidence if you go to tribunal next time you apply for a statement.
Sorry if I'm teaching you to suck eggs.