“[15] Case law and commentary are plentiful in the taking the same view in the situation where the revised taxable income of a taxpayer is increased taking account of prior adjustments, in that that constitutes a very clear indication for treating the assessment as being a “new assessment” instead of an “additional assessment”.
…
“[17] In the same way, the authors who have weighed on the distinction between a “new assessment” and an “additional assessment” consider that the increase in total taxable income on a notice of assessment indicates that it constitutes a new assessment and not an additional assessment …” [My translation.]
The consequence for a taxpayer, especially a large corporation such as Rio Tinto, can be the need to file a separate objection or revise its Notice of Appeal. (See e.g., ITA s. 162(7) for the basis for the distinction between the additional assessment or and a fresh reassessment.)