“The element of guess-work and the almost unavoidable inaccuracy in a properly made best of judgment assessment, as the cases have established, do not serve to displace the validity of the assessments, which are prima facie right and remain right until the taxpayer shows that they are wrong and also shows positively what corrections should be made in order to make the assessments right or more nearly right. It is also relevant, when considering the sufficiency of evidence to displace an assessment, to remember that the facts are peculiarly within the knowledge of the taxpayer.”
“… so far as the discovery point is concerned, once the Inspector comes to the conclusion that, on the facts which he has discovered, Mr Jonas has additional income beyond that which he has so far declared to the Inspector, then the usual presumption of continuity will apply. The situation will be presumed to go on until there is some change in the situation, the onus of proof of which is clearly on the taxpayer.”
“(i) if it appears that no penalty has been incurred, set the determination aside, (ii) if the amount determined appears to be correct, confirm the determination, (iii) if the amount determined appears to be excessive, reduce it to such other amount (including nil) as it considers appropriate, or (iv) if the amount determined appears to be insufficient, increase it to such amount not exceeding the statutory maximum as it considers appropriate.”