47. Notwithstanding section 46, the Minister shall not include in computing the duties, upon a reassessment, additional assessment or assessment made after the expiry of four years from the day mentioned in subparagraph ii of paragraph b of subsection 2 of section 46, an amounti. that the beneficiary, executor, trustee or administrator has established cannot reasonably be regarded to have been the object of a waiver contemplated in subparagraph ii of paragraph b of subsection 2 of section 46, and
ii. in respect of which the beneficiary, executor, trustee or administrator establishes that the failure so to include it did not result from any misrepresentation attributable to neglect or wilful default or from any fraud in filing his return or in supplying any information provided for under this act.