Admission of additional evidence on appeal is confined to exceptional circumstances to avoid miscarriage of justice; appellate courts should not go beyond the lower court record and may admit extra evidence only to remove a real lacuna or when the record is inadequate to pronounce a satisfactory judgment. Lack of due diligence, tactical omission, negligence, inadvertence, or the mere significance of a document do not justify admission. The same restrictive principle governs GST tribunals, so parties must present complete grounds and evidence at the adjudicatory stage. (AI Summary)
TaxTMI