(4)The provisions of sub-sections (1), (2) and (3) shall not apply if the owner, or the person who has had a beneficial interest in the securities, proves to the satisfaction of the Assessing Officer that—(a)there has been no avoidance of income-tax; or(b)the avoidance of income-tax was exceptional and not systematic and also that in any of the three preceding years any avoidance of income-tax by a transaction of the nature referred to in sub-sections (1), (2) or (3) was not there in his case.
