There are special allowences and rules for special needs Scouts.
The Scout must complete as many of the standard requirements as he can.
The unit submits to council advancement committee a request detailig which standard requirements the Scout has complete and suggests alternates for thise he can’t complete. A statement from a licenced halth-care must accompany the request, and, in the case of a mental disabilitym an evaluation from a certified educational administraor must be filed as well.
There is lots more about it for the Scout and Special Training for the Adult Leader.
Well, that would explain it. :)