(1) A tribunal has no jurisdiction to decide whether a person to whom an application for compensation relates is or is not, or was or was not, a worker at any time material to the application.
(2) A decision of a tribunal is not admissible in evidence as proof, or as tending to prove, that a person to whom an application for compensation relates, or who has sustained an injury, is or is not, or was or was not, a worker at any time material to the application.