Construction of tax payable under notice of demand bars application of section 13 to specified prior penalty orders. If the Supreme Court had earlier held on appeal that the phrase 'the amount of the tax, if any, payable by him' in clause (i) of section 271(1) means the tax payable under a notice of demand under section 156 issued pursuant to an assessment order, then section 13 shall not apply and shall be deemed never to have applied to the penalty order in respect of that assessee for that assessment year.