In Hilder, the appellant argued a lack of parity with a co-accused, Sandhu. Although Sandhu was convicted of more serious offences, Lasry AJA approved of the lesser sentence given to him as justified by early admissions to the crimes, cooperation, and an absence of prior convictions. Hilder did not have these things to call on in mitigation.
Maxwell P agreed, but also critiqued the current phraseology applied to parity [beginning at 37]:
As regards the parity ground, I express the hope that the phrase ‘justifiable sense of grievance’ will in due course disappear from the discourse in this area. It is, of course, a phrase of the most impeccable pedigree but, with respect, it seems to me to distract attention from the true nature of the question which must be addressed when the ground of parity is advanced. The question is whether it was reasonably open to the judge in the circumstances of the case to differentiate – or fail to differentiate – between the co-offenders in the way he or she did: Teng v The Queen (2009) 22 VR 706. After all, it is the legality of the judge’s decision, not the offender’s sense of grievance, justified or otherwise, on which attention must be focused.
Expressing the test in this way – ‘was it reasonably open?’ – seems to me to have the advantage not only of placing the parity ground squarely within the analytical framework of sentence appeals but of underlining the difficulty of making good the ground. There is a close analogy with the stringency of the test of manifest excess. For this ground to succeed, it must be shown that the conclusion as to sentence differentials was not reasonably open. As with manifest excess, that should be viewed as a difficult hurdle to surmount, as this Court recently said in Director of Public Prosecutions v Karazisis  VSCA 350, –.
39 What I said in R v Stuttard  VSCA 112, [at 26] in relation to manifest excess applies equally to parity. Where a judge has carefully considered all of the relevant sentencing considerations applicable to the respective co-offenders, a ground of parity will rarely succeed. In those circumstances it will be necessary for an appellant to show that, despite the sentencing task having been carefully and conscientiously carried out, nevertheless, the conclusion as to differentiation is so obviously wrong that this Court is constrained to conclude that the sentencing discretion miscarried as a matter of law.
The President has had a decisive policy-setting role in Court of Appeal sentencing judgments (like Verdins and Winch) in recent years. A sentence appeal relying on manifest excess has proven difficult to make good in recent years. It's likely that the same scrutiny will now be applied to justifiable sense of grievance parity cases.
Instead of asking, 'does the appellant have a sense of grievance, and are there reasonable grounds for that?' the correct question is, 'was it reasonably open to the sentencing judge to sentence as they did'. That superficially appears a more onerous test to satisfy.