It's a sadly common issue where a person applying for DLA has more than one health issue, but DWP only seek report from one specialist. Have they also asked for a school report? However, as the issue is the difference between middle rate care and higher rate care, that means care needs at night. The tribunal panel ask parents as they're the ones who are with the child though the night, not the consultant(s) nor school teachers. However, the key words are care that is "reasonably required", which means that while care may be given through the night, if it is considered unecessary, then higher rate care won't be awarded. You would be well advised to get reports or letters from any other medical specialists who deal with Graham eg consultants, nurses, physiotherapists, occupational therapists, psychologists etc.