In a claim involving a minor who is employed illegally under State law, the Commission may double the amount of compensation and death benefits authorized by this title. When the Commission awards double compensation or death benefits under subsection (a) of this section: the employer of the minor is solely liable for the increased amount of compensation or death benefits; and an insurance policy may not provide for payment or indemnification of the employer of the minor for payment of the increased amount of compensation or death benefits. For purposes of this title, a certificate of the Commissioner of Labor and Industry is conclusive evidence of the legality of any employment of a minor.