It would concern me very much, and I would want to know exactly what he meant by it, and what they do do to support children with SEN relevant to my child's needs.
I would then make up my mind about the school and if I thought they were not offering what they should, not offering what any school should offer in order to support my child, or if his comments were discriminatory I would go to the governors - or probably ask on MN what to do, and Admission or Tiggy or prhbridge47 would give me some very good advice, which I would follow.
I doubt that advice would involve posing outside the school and making my DS's personal circumstances available for all to see and comment on in the local rag.