In short, Kourakis CJ considered those provisions — found in the Criminal Law (Clamping, Impounding and Forfeiture of Vehicles) Act 2007 (SA) s 12 — and held they are invalid because they require a court to act inconsistently with the judicial integrity implication from Kable v DPP (1996) 189 CLR 51.
As an aside, this is a really easy-to-read judgment, because His Honour set out in the first 10 paragraphs — two-and-a-bit pages — what the appeal was about, and which of the two arguments for the appellant he accepted and rejected. That means when you read it, you already know the structure and the significance of his analysis. It's really nice to see for such a complex area. It's a style of writing journalists call inverted pyramid structure. The great thing about seeing this is a judgment is that when judges do it, it leads the way for advocates every where to follow. IMHO that can only be a Good Thing! (Bryan Garner says much the same thing in many of his texts on written advocacy.)
Two provisions to note from the SA legislation are s 4 and s 12.
Section 4 provides:
4—Powers under Act in addition to other penalties
(1) A power exercisable under this Act is exercisable in addition to any other penalty that may be imposed on a person in relation to a prescribed offence.
(2) However, a court must, in imposing another penalty on a person in relation to a prescribed offence, have regard to any exercise of powers under this Act.
Section 12 of the SA legislation provides:
12—Court order for impounding or forfeiture on conviction of prescribed offence
(1) Subject to section 13, if this Part applies to a conviction for a prescribed offence, the court that records the conviction must, on the application of the prosecution—
(a) order that the motor vehicle specified in the application is forfeited to the Crown if—
(i) the offence is a forfeiture offence; or
(ii) the convicted person has been found guilty of or expiated at least 1 other prescribed offence committed or allegedly committed within 12 months of the date of the offence; or
(iii) the convicted person has been found guilty of or expiated at least 2 other prescribed offences committed or allegedly committed within 10 years of the date of the offence;
(b) order that the motor vehicle specified in the application be impounded by the relevant authority for a period not exceeding 6 months if—
(i) the convicted person has been found guilty of or expiated 1 other prescribed offence committed or allegedly committed within 10 years of the date of the offence; and
(ii) paragraph (a) does not apply.
(1a) If the court makes an order under subsection (1), it must also order that the convicted person pay to the relevant authority fees calculated in accordance with the regulations in relation to the forfeiture or impounding of the motor vehicle.
This is roughly equivalent to Road Safety Act 1986 (Vic) s 84T. The difference is that s 84T says a court may order forfeiture of a car, subject to s 85Z. The difference is important.
Section 85Z purports to limit a Court's discretion to order forfeiture, and I suspect it was probably intended to operate in much the same way as the SA legislation. But, on a careful reading, what is seems to actually do is restrict a Court's discretion to not order forfeiture, but only when it does so on the basis of exceptional hardship. (I discussed that exception in May 2011 here.)
So, if a Court declined to order forfeiture on the ground that the punishment would be be more severe than is necessary to achieve the purposes of sentencing as set down in s 5(3) of the Sentencing Act, Road Safety Act s 85Z says absolutely nothing about that. Nor does the second reading speech or explanatory memorandum for the amendments that introduced s 85Z. I think this view is supported by s 84D, which provides:
84D. This Part does not affect other penalties
The impoundment, immobilisation or forfeiture of a motor vehicle under this Part arising out of the commission of a relevant offence is in addition to, and does not limit or otherwise affect, any penalty that may be imposed on the person for the relevant offence other than under this Part.
The reason I say this is important is because it is the mandatory nature of vehicle forfeiture that resulted in the SA Supreme Court holding that those provisions were invalid. If the Victorian provisions are mandatory, then they are probably invalid too.
Now, if your eyes are already glazing over getting your head around all these different sections, don't forget our aidé memoire for the vehicle impoundment provisions available here.
Prospective or retrospective operation?
The appellant was ordered to forfeit his car to The Man after he was found guilty on 10 January 2011 of drink-driving on 4 December 2010. The drink-driving offence — or 'confiscation offence' — was prescribed as a forfeiture offence from 16 December 2007, when the Criminal Law (Clamping, Impounding and Forfeiture of Vehicles) Act 2007 commenced operation.
The appellant argued the legislation was retrospective for two reasons. First, because the qualifying offences weren't qualifying offences when he committed them.
A person is liable to forfeiture when they commit a qualifying offence and have been found guilty or expiated two other prescribed offences — termed 'qualifying offences' by Kourakis CJ — within ten years of the confiscation offence.
This seems simple enough, but the legislation doesn't say the ten years must run before the confiscation offence.
If it only operates historically — if only qualifying offences committed before the confiscation offence can be considered — it won't operate retrospectively, according to Kourakis CJ.
Even if the qualifying offence wasn't prescribed as a qualifying offence when the person committed the offence.
That's because the person isn't liable to forfeiture of their car until they commit the confiscation offence. The legal effect of the qualifying offences isn't changed until then, so there isn't any retrospective operation:  – .
The second argument by the appellant was that because qualifying offences could potentially be relied on after the confiscation offence, even though they might not have been prescribed as qualifying offences when they were committed (and, for that matter, when the forfeiture offence was committed too), the legislation breached the prohibition against retrospectivity.
The Court dealt with that by referring to s 10, which provides that a person is taken to have been found guilty of or to have expiated a prescribed offence if the person has been found guilty of or expiated an offence that is a prescribed offence (as defined) at the time the application is made.
(I reckon that means all these provisions can only operate as you and I would expect: the driver must have two 'relevant priors' that pre-date the confiscation offence. Only then can the prosecution make a forfeiture application. If that's right, it shoots down the whole application-up-to-ten-years-after-the-event concern the Court had in this case.)
One point neatly resolved in this case is the query I posed in my earlier post: what's the position for a driver who committed relevant offences that weren't relevant offences at the time of offending? At  - , the Court listed four reasons why it was enough if the offences were prescribed — 'relevant offences' in the Victorian nomenclature — at the time of the application at Court. (I won't rehash them here; you can read them for yourself if you need to.)
At  –  the Court dealt with the appellant's alternative argument that forfeiture amounted to double-punishment, additional to the sentence he received for the confiscation offence.
His Honour held the forfeiture didn't offend the prohibition on double-punishment.
The forfeiture order can only be made upon the offender’s conviction for the confiscation offence and it is with respect to that offence that forfeiture is imposed as a penalty. It is a well established sentencing principle that, all other things being equal, an offender with an antecedent criminal history, will receive a more severe penalty for a particular offence, than a first offender. The greater penalty is not an additional punishment for the other offences but reflects the heightened need for personal deterrence. So too for forfeiture imposed under the Forfeiture Act, the commission of the qualifying offences is a reason for making the forfeiture order, but it is made on conviction of the subsequently committed confiscation offence. The distinction is subtle, but is one of substance and not just semantics: at .
Maybe I missed something, but to me, the distinction is so subtle that it's non-existent. If a Court sentences someone for the confiscation offence, and takes into account their antecedent history and decides the offender deserves a bigger whack than someone with no history, and then on some later date, following an application from the prosecution, confiscates the driver's car, how can that be anything but a further punishment? Indeed, at , His Honour even noted, "The confiscation of an asset of such relative importance is undoubtedly a severe penalty. It is also a symbolic penalty. The primary effect of a forfeiture order is plainly punitive and for that reason it also operates as a general and personal deterrent." Sounds like a duck; walks like a duck...
His Honour did hold that forfeiture orders made based on qualifying offences committed in the future would amount to double-punishment. (I'm not convinced that can occur, given the operation of s 10 discussed above.) In any event, His Honour considered that Parliament indicated it intended to abrogate the rule against double-punishment. That might be so, but I don't understand how Parliament could lawfully do so. Section 50 of the Acts Interpretation Act 1950 (SA) — almost identical to s 51 of the Interpretation of Legislation Act 1984 (Vic) — expressly provides that a person is not liable to double-punishment. And s 4(2) of the SA forfeiture legislation seems to accept that, stating, that a court must, in imposing another penalty (emphasis added) on a person in relation to a prescribed offence, have regard to any exercise of powers under this Act.
I argue that forfeiture does amount to additional punishment. The way that a court can avoid infringing the prohibition against double-punishment is to impose a sentence for a confiscation offence contemporaneously with the forfeiture application, so that it's part and parcel of the overall instinctive synthesis. Contrast this with things such as sex offender registration and monitoring in Victoria, where s 5 of the Sentencing Act expressly prevents a court from considering the consequences of those ancillary orders.
In Kable v DPP (NSW) 1996) 189 CLR 51 the High Court considered the validity of State courts. Though State courts are subject to State Constitutions, because they can exercise federal power under s 39 of the Judiciary Act 1903, they must conform with prescribed requirements for judicial institutions in Chapter III of the Constitution of Australia. In Momcilovic, the High Court referred to the Kable principle as the repugnancy doctrine. Whatever you call it, the basis idea is that courts can't be legislatively compelled to make decisions that have the effect of just rubber-stamping executive decisions. For example, legislation was invalid when it required a court to make a control order for people only because they were bikies, with no judicial consideration of their guilt or risk they posed: South Australia v Totani (2010) 242 CLR 1.
The appellant succeeded on this point, with the Court accepting that the confiscation provisions offended the judicial integrity principle from Kable.
 In my respectful opinion, the above cited passages show that at the core of the judicial integrity implication lies a requirement that there be a rational connection between the adjudicative function invested in the court and the powers it must, or may, exercise. Legislation conferring a jurisdiction or power on a court will only be compatible with the judicial integrity implication if the orders which the court must, or may, make have a rational connection to findings of fact, and judgments on those facts, which the court itself has made.
 Questions of incompatibility with the judicial integrity implication loom larger when the legislative scheme, instead of proscribing specified conduct and providing for penalties or other orders in the case of breach, authorises, in prescribed circumstances, executive and judicial action to derogate from the otherwise lawful freedom of action, or property rights, of individuals. It is also one thing for Parliament to provide a statutorily prescribed mandatory penalty for criminal conduct and quite another for it to allow the executive to nominate in its application to the Court an additional penalty of its choosing which a court must impose to depend on the selection...
 The scheme adopted by the Forfeiture Act has four core elements which together are incompatible with the judicial integrity implication. First, it disguises an executive decision to extract a forfeiture as an application to a court and by so doing largely immunises the decision from judicial review. Secondly, the Forfeiture Act denies that court any substantive judicial function with respect to that application by mandating the order it must make so as to ensure that the executive’s decision is given effect. Thirdly, it secures for an essentially executive order the immunity from collateral attack which only judicial orders enjoy. Fourthly, the object of the scheme is to require courts to impose a penalty selected by the prosecution in addition to the penalty they have already imposed in the exercise of the sentencing power.
 I acknowledge the dispensing power conferred by s 13 of the Forfeiture Act. However the scope of the power is limited, in the case of defendants, to cases of “severe financial or physical hardship”. The forfeiture of a motor vehicle would cause substantial financial hardship to most defendants. Something much more than the hardship which forfeiture would ordinarily cause must be shown. In the generality of cases no dispensation can be given. In any event the judicial power to exempt a defendant in a particular case on hardship grounds does not meet the constitutional objection to the nature of the primary power and the manner of its exercise.
In essence, the vice here is that the prosecution chooses if and when it will make a forfeiture application. Once made, the court is compelled to make the order if the offender comes within the scope of the legislation. There is no adjudication for the court to perform; it simply must make the order, unless some very narrow exceptions apply.
So long as this legislation is said to be mandatory or obligatory, I think it's likely to fall foul of the repugnancy doctrine.
For good measure, another Constitutional argument that might crop up is the prohibition on acquisition of property except on just terms, in s 51(xxxi) of the Constitution. I'm no Constitutional lawyer, and I haven't looked into the point in any detail, but I wonder if there's a difference between a penalty — where the court can require an offender to give up a fungible asset in the form of money — and forfeiture of a lawfully owned and specified chattel that is not necessarily associated with the offence that founds the forfeiture?
Apparently the South Australian Attorney-General is appealing this judgment, so it might be overturned on appeal, or else there is no doubt the government will try to amend the legislation.