(a) the board of referees failed to observe a principle of natural justice or otherwise acted beyond or refused to exercise its jurisdiction;
(b) the board of referees erred in law in making its decision or order, whether or not the error appears on the face of the record; or
(c) the board of referees based its decision or order on an erroneous finding of fact that it made in a perverse or capricious manner or without regard for the material before it.