Where a certificate of insurance has been issued to the person by whom a policy has been effected, the happening in relation to any person insured by the policy of any such event as is mentioned in sub-section (1) or sub-section (2) of section 150 shall, notwithstanding anything contained in this Chapter, not affect any liability of that person of the nature referred to in clause (b) of sub-section (1) of section 147; but nothing in this section shall affect any rights against the insurer conferred under the provisions of sections 150, 151 and 152 on the person to whom the liability was incurred.