Aggravating factors at sentencing do not include delay in the proceedings if the defendant was not responsible for that delay. Nor do they necessarily include exercise of the right to put the prosecution to proof: Hassen Eid -En Rummun v The State of Mauritius (Mauritius)  UKPC 6 (7 February 2013), , .
Those propositions of law depart from the usual approach to delay. It is conventional to ask, to what extent is it a mitigating factor that the defendant has been deprived of the right to a trial without undue delay, and to what extent is it a mitigating factor that the defendant has pleaded guilty?
Where there may have been a breach of a defendant's constitutional right, it is the duty of the sentencing court to examine whether any such breach should have an effect on the disposal of the case, whether or not that issue has been raised by counsel: . The seriousness of the offending may be such as to outweigh the effect of the breach, but the breach is a factor that must be considered: .
In this case delays seem to have been largely due to a co-defendant's strategy, although there were also delays due to the unavailability of prosecution witnesses including police officers. The facts needed clarification, and the case was remitted to the Supreme Court of Mauritius, but it is implicit in the Board's approach that where a co-defendant or a prosecutor is causing delay, the defendant should object to that delay and ask that his objection be recorded, because at sentencing his attitude to the postponement of the proceedings will be closely examined: , applying Celine v State of Mauritius  UKPC 32, and Boolell v State of Mauritius  UKPC 46 (noted here 18 October 2006). But mere acquiescence in delay is not the same as actively promoting delay .
While there is no doubt that an early plea of guilty is a mitigating factor, courts have been careful to distinguish the absence of a mitigating factor from the presence of an aggravating factor: see for example Republic of Croatia v Snedden  HCA 14 (noted here 19 May 2010). Failure to plead guilty at an early stage can result in loss of a sentence reduction, but it does not – or should not – lead to an additional penalty. This reasoning satisfies legally trained minds, but defendants can find it difficult to follow. It is, however, important not to coerce guilty pleas: Hessell v R  NZSC 135 at -, discussed here on 16 November 2010.
Here is the Board's treatment of this point :
The word "penalised" here is inappropriate for legal discourse. There is a tendency to pussy-foot around points that should be stated absolutely. What do "some caution" and "anxious scrutiny" mean?
If the defendant "is entitled" to put the prosecution authorities to proof, how can exercising that entitlement result in punishment? It may result in loss of a mitigating factor, but it would be wrong to treat it as an aggravating factor. Similarly it would be wrong to treat trial delay as an aggravating factor, whereas it would be correct to treat unjustified trial delay caused by the defendant as grounds for reducing or eliminating the mitigating effects of loss of the right to a trial within a reasonable time. Or at least that is what this decision recognises.
It is unfortunate that the Board was so brief on this point. On what principled basis should a defendant be deprived of the full mitigating effect of unreasonable trial delay? The defendant has already lost the mitigating effect of an early guilty plea. The basis for mitigation arising from an early guilty plea is the pragmatic one of encouraging the saving of court time and the associated expense of trial. There is a link between the guilty plea and the saving of time and cost. On the other hand, mitigation arising from breach of the right to trial without undue delay is based on encouraging prosecution efficiency. If the prosecution process has been inefficient to the extent of being unreasonably slow, where is the link to the defendant's plea? Without judicial clarification we can properly wonder whether the Board is correct to recognise that a plea of not guilty may reduce the defendant's remedy for unreasonable delay by the prosecution.