Taub v R

Judgment

1. SIMPSON JA: On 16 March 2015 the appellant was arraigned in the District Court on an indictment that charged that between 11 July 2008 and 11 August 2011 he manufactured not less than the large commercial quantity of a prohibited drug (methylamphetamine), an offence against s 24(2) of the Drug Misuse and Trafficking Act 1985 (NSW) ("the DMT Act"). A large commercial quantity of methylamphetamine was then 1 kilogram. (The DMT Act has since been amended so that a large commercial quantity is 500 grams.) By s 33(3)(a) of the DMT Act, the offence is subject to a maximum sentence of imprisonment for life. By Pt 4 Div 1A of the Crimes (Sentencing Procedure) Act 1999 (NSW) ("the Sentencing Procedure Act"), a standard non-parole period of 15 years is prescribed.
2. The appellant entered a plea of not guilty and a trial by jury proceeded. Although the only charge on the indictment was of manufacturing not less than the large commercial quantity of methylamphetamine, the jury was directed as to two alternatives - manufacture of not less than the commercial quantity (250 grams) and manufacture of methylamphetamine (of no specific quantity). Manufacture of not less than the commercial quantity of methylamphetamine carries a maximum term of imprisonment of imprisonment for 20 years (DMT Act, s 24(2)(a)), with a standard non-parole period of 10 years (Sentencing Procedure Act, Pt 4 Div 1A). An offence of manufacturing methylamphetamine carries a variable maximum penalty depending upon the quantity involved - the offence may be disposed of summarily, with a maximum penalty of imprisonment for 2 years (DMT Act, s 30(3)). If dealt with on indictment, such an offence is punishable by imprisonment for a maximum term of 15 years.
3. On 24 March 2015 the jury returned a verdict of guilty of the offence on the indictment. On 29 May 2015 the appellant was sentenced to imprisonment for 9 years and 4 months, commencing on 11 February 2015, with a non-parole period of 7 years, which will expire on 10 February 2022.
4. The appellant now appeals against the conviction. He has not sought leave to appeal against the sentence imposed.
5. Two grounds of appeal are pleaded. The first alleges error on the part of the trial judge in admitting expert opinion evidence, as to which a pre-trial voir dire had been conducted. The second, which is entirely based on the same expert evidence, asserts that the verdict of guilty was unreasonable and could not be supported on the evidence.
6. By s 6 of the Criminal Appeal Act 1912 (NSW), an appeal against conviction is to be allowed if this Court is of the opinion that the verdict of the jury should be set aside on any of the following grounds:

• that the verdict is unreasonable or cannot be supported having regard to the evidence;
• that the judgment of the court of trial should be set aside on the ground of the wrong decision of any question of law; or
• that on any other ground whatsoever there was a miscarriage of justice.

1. The first ground of appeal invokes the second of these permitted grounds. It must be tested against the evidence and material that was available to the trial judge at the time the decision in question was made: R v Fletcher (2005) 156 A Crim R 308; [2005] NSWCCA 338. It is not affected by events that occurred in the trial subsequently. That does not mean that evidence, even if correctly admitted, cannot be the subject of appellate review, but then the ground invoked is that of the third variety, miscarriage of justice.
2. I mention this because, although the first ground is limited to a challenge to the admission of the expert evidence, some of the submissions made purport to find support in events that occurred in a late stage of the trial, which, it was contended, affected the weight of the evidence.

The Crown case

1. Since the issues raised on appeal are relatively confined, it is possible and appropriate to state the facts and circumstances of the Crown case with brevity.
2. From early in 2008 the appellant had been the lease-holder of a residential property at Leppington. Erected on the property was a house, which was divided into two sections, and a garage. The appellant and his family occupied one part of the house. A tenant named Sorin Livadariu occupied the other part.
3. On 11 August 2011 a number of police, led by Detective Senior Constable Keiran Deas, executed a search warrant at the premises. Initially they searched both parts of the residential accommodation. They then approached the garage and opened the door. Detective Deas formed the view that there were in the garage items consistent with the manufacture of prohibited drugs. He closed the door and arranged for specialist police to attend. These were officers of the Drug Squad Chemical Operations Unit. Accompanying them was a forensic chemist, Mr Peter Ballard, who was then employed by the Forensic Services Group of the NSW Police Force. Mr Ballard's duties included providing expert support for investigations into clandestine drug laboratories.
4. No substantial amount of methylamphetamine was discovered, although there were indicia of drug manufacture. The search of the garage yielded a number of items that were capable of evidencing illicit drug production. These included (but were not limited to):

• a modified beer keg that contained more than 27.6 kilograms of a brown coloured, strongly alkaline liquid. The keg stood on bricks, with a hollow underneath, capable of allowing a heat source, such as a gas ring burner, to be inserted under the keg;
• a gas ring burner and an LPG cylinder, which were adjacent to the beer keg;
• a modified pressure cooker;
• a glass vessel with a glass rod and rubber stopper, containing 6.62 grams of a clear, colourless liquid;
• a 20 litre "sour cream" plastic bucket containing 7.755 kilograms of a dark brown liquid; and
• a "Lafarge" plastic bucket containing 9.12 kilograms of a dark brown liquid. (Why the quantities of the liquid were given in kilograms as distinct from litres is not clear.)

1. The liquid in the beer keg was, on analysis, found to contain a low concentration of pseudoephedrine (a substance known to be used as a precursor in the manufacture of methylamphetamine), a low concentration of methylamphetamine, and a substance called dimethyl sulfone. Iodine was also present. Alkaline liquid containing low levels of methylamphetamine were also found in the glass vessel, and in the two plastic buckets.
2. The occasion of the execution of the search warrant was not the first time that police had investigated, and discovered, drug manufacture at the premises during the appellant's occupancy. On 30 January 2009 police attended the property (in relation to inquiries unassociated with drugs). While on the premises, they located prohibited drugs in the garage. Among the items seized were a glass dish containing 3.64 grams of pseudoephedrine, a plastic container in which was 1.25 grams of methylamphetamine, a plastic bowl containing 9.49 grams of pseudoephedrine, 10 tablets of pseudoephedrine, and a resealable plastic bag containing 1.16 grams of methylamphetamine.
3. The appellant was arrested and charged with possession of those drugs. He entered a plea of guilty to each charge. This evidence was admitted in the trial, apparently without objection. It was tendered by the Crown as part of its evidence that a drug manufacturing process had taken place on the premises, that the drug was methylamphetamine, and to show the appellant's association with the drug. It is to be noted that 30 January 2009 was within the period specified in the present indictment as the period during which the appellant was engaged in manufacturing methylamphetamine and potentially relevant to the quantity of the drug the appellant was charged with manufacturing. (It may also have been the intention of the Crown to tender this evidence as evidence of tendency and/or coincidence under ss 97 and 98 of the Evidence Act 1995 (NSW) but this is not at all clear.)
4. Given that only a very small quantity of methylamphetamine was located at the premises, the Crown case depended heavily on the opinion evidence of an expert (Mr Ballard) tendered under s 79 of the Evidence Act to prove two elements of the offence charged; that is, manufacture of the drug, and the quantity.
5. Essentially, in order to prove the latter element, the Crown case was circumstantial. It sought to prove the quantity of drug manufactured by Mr Ballard's opinion evidence, based on observations made by him at the scene, together with the results of forensic analysis of items taken from the premises, particularly the liquid contained in the beer keg and the buckets, and the inferences Mr Ballard drew from those circumstances.

Admissibility of opinion evidence: principles

1. The first ground of appeal is directed to the admissibility of Mr Ballard's opinion evidence. It is convenient, therefore, to set out the principles relevant to the admissibility of opinion evidence, before examining the content of the evidence.
2. Where evidence of an opinion is admissible, it is admissible in order to prove the existence of a fact relevant to the proceeding in which evidence of the opinion is sought to be tendered. So much is apparent from ss 76(1) and 79(1) of the Evidence Act, which state, respectively, the exclusionary "opinion rule" and an exception to the opinion rule, permitting, in specified circumstances, the opinion evidence of experts. Those sections are in the following terms: "76(1) Evidence of an opinion is not admissible to prove the existence of a fact about the existence of which the opinion was expressed. … 79(1) If a person has specialised knowledge based on the person's training, study or experience, the opinion rule does not apply to evidence of an opinion of that person that is wholly or substantially based on that knowledge."
3. The Crown sought, by Mr Ballard's opinion evidence, to prove two essential facts. They were: (i) that methylamphetamine had been manufactured on the premises; and (ii) that the quantity manufactured was not less than 1 kilogram.
4. The tender of opinion evidence under s 79 presents, in stark form, difficulties in distinguishing between the admissibility of the opinion of which evidence is sought to be admitted, and the weight that may be attributed to that evidence if it is admitted. In Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705; [2001] NSWCA 305, Heydon JA (as he then was) stated (at [85]) the prerequisites or criteria that must be met before expert opinion evidence may be admitted under s 79. Those relevant to the present case concern the extent to which it is necessary, as a condition of admissibility, for the tendering party to prove the truth of the facts and assumptions on which the opinion is based.
5. Paragraph [85] of Makita was not his Honour's last word on the subject. In Dasreef Pty Ltd v Hawchar (2011) 243 CLR 588; [2011] HCA 21, Heydon J (then a justice of the High Court) identified three relevant common law rules applicable to the tender of opinion evidence. It is clear that what his Honour was saying was that these three rules go to the question of admissibility and not to weight. His Honour gave the three rules to which he referred the labels "the assumption identification rule", "the proof of assumption rule" (also called "the basis rule") and "the statement of reasoning rule" (at [61]). As its name suggests, the "assumption identification rule" requires specification of the assumptions, or the facts, upon which the opinion is based. The "statement of reasoning rule" is also self-explanatory, and requires that the expert expose the reasoning process that led to the opinion formed and expressed.
6. At [100] Heydon J concluded that the common law "assumption identification rule" continues to apply to the tender of opinion evidence by an expert under s 79, saying: "… the articulation of all significant factual assumptions is a precondition to admissibility when expert evidence is tendered under s 79."
7. His Honour reached (in somewhat more muted terms) a similar conclusion in relation to "the proof of assumption rule". He explained the "proof of assumption rule" at [66] as : "An expert opinion is not admissible unless evidence has been, or will be, admitted, whether from the expert or from some other source, which is capable of supporting findings of fact which are sufficiently similar to the factual assumptions on which the opinion was stated to be based to render the opinion of value." (italics added) Expert opinion not shown to have been based on facts capable of being proved by evidence in the proceedings is inadmissible because it is irrelevant: see Evidence Act, s 56. An opinion not based on provable facts has no probative value (see s 55) and, hence fails the admissibility test.
8. To my understanding, on Heydon J's analysis, proof of the truth of the assumptions or facts on which the proffered opinion is based is not a condition of admissibility; the condition of admissibility is that there be available admissible evidence ultimately to prove, to the satisfaction of the tribunal of fact, the truth or accuracy of the assumptions on which the opinion is based. Where opinion evidence has been admitted on the basis that evidence to prove the facts on which the opinion is based will be called, and that evidence is not forthcoming, the admission of the evidence might be reconsidered ([88]).
9. Finally his Honour accepted (conformably with the plurality - see [37]) that "the statement of reasoning rule" applies to evidence tendered under s 79 - that is, the evidence must disclose the reasoning that leads to the formation of the opinion. Specifically, he observed (at [129]) that admissibility does not depend upon the reasoning being accepted as correct; it depends upon the reasoning being stated. The correctness of the reasoning is a matter for consideration at the end of the trial.
10. The plurality in Dasreef refined Heydon JA's seven admissibility criteria in Makita to two:

• that the witness who gives the evidence "has specialised knowledge based on the person's training, study or experience"; and
• that the opinion expressed in the evidence by the witness "is wholly or substantially based on that knowledge" ([32]). What was in issue in Dasreef was whether the opinion expressed by the witness proffered as an expert was based on the witness' specialised knowledge based on his training, study or experience.

1. The plurality added (citing [85] of Makita) that: "… ordinarily … 'the expert's evidence must explain how the field of 'specialised knowledge' in which the witness is expert by reason of 'training, study or experience', and on which the opinion is 'wholly or substantially based', applies to the facts assumed or observed so as to produce the opinion propounded'." ([37])
2. This, it appears to me, states a third criterion of admissibility. Their Honours then emphasised (at [42]) that satisfaction of the criteria is a matter that goes to the admissibility of, not the weight to be attributed to, the opinion evidence.
3. The plurality declined to engage with the question whether the "proof of assumption rule" (what their Honours called "the basis rule") existed at common law; such a rule, their Honours said, was directed to the facts of a particular case. From that it might be inferred that their Honours considered that whether the facts upon which the opinion was based are established as true is a question that goes not to admissibility, but to the weight to be attributed to the opinion expressed. This is also the analysis of Schmidt J in Kyluk Pty Ltd v Chief Executive, Office of Environment and Heritage (2013) 298 ALR 532; [2013] NSWCCA 114 at [176]-[177].
4. It seems to me that the difference between Heydon J and the plurality lies in the rigour with which Heydon J would insist on the availability of evidence to prove the truth, or correctness, of the assumptions or facts forming the foundation of the opinion as a condition of admissibility and at the time admissibility is being considered. It is not the position of Heydon J that, before evidence of the opinion could be admitted, it was necessary that the assumptions or facts be proved to be true or correct; rather, it was necessary that it be shown that ultimately the evidence would be capable of establishing that the facts or assumptions were true or correct. To insist on the availability of evidence to prove the truth of the assumptions enhances efficiency of the trial process (see [127]). Whether the evidence succeeds in establishing the truth of the facts is a question for the trier of fact.
5. The plurality, on the other hand, would allow admission of the opinion evidence provided the reasoning was exposed, reserving to the tribunal of fact whether the evidence was sufficient to establish the truth or correctness of the assumptions or facts. Failure to prove the truth of the assumptions would render the opinion evidence of little or no value.
6. The view that the truth of the assumptions on which an expert opinion is based need not be proved as a condition of admissibility was expressed by Spigelman CJ in Australian Securities and Investments Commission v Rich (2005) 218 ALR 764; [2005] NSWCA 152 (predating Dasreef). At [136], after lengthy discussion, Spigelman CJ (with whom Giles and Ipp JJA agreed) said: "The issue for a trial judge is whether the opinion expressed to be based on the facts proved or assumed is correct. In determining this issue, the judge will have regard, amongst other things, to the reasoning process (based on those facts) used by the expert. The mere fact that the expert's opinion is based on facts that are assumed (and not proved) at the time the expert gives evidence is no reason to exclude the evidence at that stage. The assumed facts may be proved later by other evidence. The fact that the opinion was initially formed or later reinforced by reference to other facts, not said by the expert in his evidence to be proved or assumed, is irrelevant to the question of admissibility. Once the opinion is capable of being based on the proved facts, it is admissible. The fact that the expert's opinion was at one time - or even still is - reinforced by undisclosed facts and reasoning processes is irrelevant to the admissibility of the opinion (although these matters may go to weight)." (italics added) At [105] he had said that the "prime duty" of an expert is to identify the facts and reasoning process asserted as justifying the opinion. I take this to mean that, if the facts and reasoning are adequately disclosed, the opinion is admissible (even if it is subsequently found to be flawed, or wrong). The purpose of the rule is to ensure that the tribunal of fact is in a position to evaluate the opinion. That is essentially in conformity with the approach taken by the plurality in Dasreef.

The expert evidence

1. Mr Ballard provided a statement that purported to be "an expert certificate" under s 177 of the Evidence Act. Whether the statement could properly be called a s 177 certificate does not need to be decided. It went further than envisaged by s 177, particularly and relevantly, s 177(1)(c). It may properly be treated as a witness statement, which included both factual material detailing his observations at the premises and the opinions he had formed from those observations and the results of forensic testing of the items seized.
2. At the commencement of the document, Mr Ballard outlined his formal academic qualifications, and his experience, which relevantly included attendance at the premises of suspected clandestine drug laboratories, as well as attendance at training courses related to illicit drug manufacture.
3. In the document Mr Ballard gave a brief account of his attendance at the property, and what he there observed and did. He also gave an explanation of processes by which methylamphetamine can be, and is, manufactured. He then stated three opinions that he had formed. They were: (i) that the beer keg was used in the process of manufacturing methylamphetamine from pseudoephedrine, and that the liquid content of the keg was waste product of the distillation process in the manufacture; (ii) that the alkaline liquid in the glass vessel and the two buckets was the waste product of separate instances of methylamphetamine manufacture; and (iii) that more than 1 kilogram of methylamphetamine had been manufactured using the equipment found in the garage at the appellant's premises.
4. The first stated opinion was not, at least with respect to the admissibility of the evidence, put seriously in issue. The third stated opinion was critical to the Crown case with respect to the count on the indictment. By the evidence of that opinion, the Crown sought to prove that the quantity of the drug manufactured on the premises was not less than the large commercial quantity, an essential element of that offence.
5. In arriving at the third opinion, Mr Ballard said that he had taken into account: "… the size of the equipment being utilised together with the quantity of waste products located."
6. He observed that the beer keg was of a suitable size for the manufacture of "kilogram quantities of methylamphetamine per batch", and that the total quantity of waste product located (more than 44 kilograms) supported that opinion, as did the evidence that more than one batch had been produced.

The trial

1. On behalf of the appellant, objection was taken to the admission of the evidence the Crown proposed to call from Mr Ballard. The specified objection was that Mr Ballard's statement failed to meet the admissibility requirements for opinion evidence stated in Makita at [85]. A pre-trial voir dire was held, in which Mr Ballard's report was in evidence, as was the transcript of evidence he had given in the committal proceedings. Mr Ballard gave evidence and was cross-examined.
2. It was made clear, both in written submissions provided to the trial judge and in oral argument, that the objection was directed to Mr Ballard's opinion as to the quantity of methylamphetamine produced. It was expressly stated that his qualification as an expert in chemistry was not challenged, and nor was his opinion that the equipment found in the garage had been used to produce methylamphetamine. All that was in issue was his qualification to express the opinion that the quantity of methylamphetamine produced was at least 1 kilogram. The objection as articulated was that, to the extent that the opinion was based on the volume of waste material, it was based "on the sheer volume of waste", and not its composition, and therefore was not based on expert training and experience, as is required for evidence of opinion to be admissible.
3. An alternative basis advanced for the rejection of Mr Ballard's opinion evidence as to quantity was that its probative value was low, and it ought to be excluded under s 137 of the Evidence Act, which provides as follows: "Exclusion of prejudicial evidence in criminal proceedings In a criminal proceeding, the court must refuse to admit evidence adduced by the prosecutor if its probative value is outweighed by the danger of unfair prejudice to the defendant."
4. In oral evidence on the voir dire Mr Ballard explained his stated opinion that the substances in the buckets represented waste material from separate instances of methylamphetamine manufacture by saying that the contents of the buckets had slightly different chemical properties.
5. He elaborated on his stated opinion that more than 1 kilogram of methylamphetamine had been manufactured. He said that the 27 kilograms of liquid in the beer keg alone was likely to have been the waste product of the manufacture of at least 1 kilogram, and possibly up to 2 or more kilograms of methylamphetamine. The liquid in each of the buckets was likely to have been the waste product of the manufacture of "at least several hundred grams, at least over 500 grams for each".
6. In cross-examination he agreed that he was aware of no (scientific) formula by which the quantity of drug manufactured could be determined by extrapolation from the quantity of waste material. He agreed that, in reaching his conclusion that each of the three containers (the beer keg and the two buckets) had been used in separate manufacturing processes, he had assumed that the processes had begun with vessels that were clean and uncontaminated.
7. In written submissions provided to the trial judge counsel for the appellant identified the bases of objection to the admission of the report as: "1 Not an opinion based wholly or substantially on the specialised knowledge stemming from Mr Ballard's training study or experience. 2 To the extent the opinion is based on his specialised knowledge or experience, it is based on assumptions that are not established by the evidence."
8. The first argument advanced on behalf of the appellant to the trial judge was that Mr Ballard's opinion as to quantity was not based on his specialised knowledge as required by s 79 of the Evidence Act, but was, rather, based on an unscientific process of reasoning from inadequate facts, the first of which was the size of the beer keg, and the second the volume of the waste material, to the exclusion of its composition. Significant reliance was placed upon an asserted failure to satisfy the requirements of admissibility stated in Makita, although the submissions were less than forthcoming about the specific way in which it was contended that the admissibility requirements were not met.
9. The second argument was that two of the assumptions on which Mr Ballard's opinion was based were not proven. One of these was that the entirety of the liquid in the vessels was the result of methylamphetamine manufacture. The other was that at least three batches of methylamphetamine had been produced, resulting in three separate containers of waste material, with varying chemical profiles.
10. The trial judge held that the evidence was admissible. She considered that Mr Ballard's scientific qualifications were sufficient to permit him to give opinion evidence based on his specialised knowledge. As mentioned above, Mr Ballard's scientific qualifications were not in issue.
11. The trial judge described Mr Ballard's opinion that the waste product was derived from the manufacture of methylamphetamine as his preliminary, or primary, opinion. She said that that opinion was the "platform" for the "secondary opinion", which was that it was likely that more than 1 kilogram of methylamphetamine had been produced in the manufacturing process.
12. The trial judge further held that the facts that were the foundation for the primary opinion had been adequately established in the evidence in the voir dire. She said that the jury would be properly directed in respect to the acceptance or otherwise of that opinion, and that, before they could turn to the secondary opinion, they had to accept the primary opinion. In the light of the submissions made to her, she did not direct her attention to whether Mr Ballard's statement adequately exposed his reasoning process.
13. She rejected the argument under s 137. Mr Ballard's opinion evidence was, accordingly, admitted.
14. The trial proceeded with the jury. Mr Ballard was the last Crown witness; he gave oral evidence and was cross-examined. Before the cross-examination had concluded, the court adjourned overnight. The next morning Mr Ballard drew to the attention of both counsel that he had, in one respect, revised his opinion. It is sufficient at this stage to say that he accepted that the revision significantly affected his estimation of the quantity of methylamphetamine which would have been manufactured in order to produce the quantity of waste product. It will be necessary, in addressing the second ground of appeal, to examine Mr Ballard's evidence in this respect more closely.
15. Mr Ballard was the final witness in the Crown case. The appellant did not give or call any evidence. Both counsel addressed, the trial judge summed up (leaving the three alternative guilty verdicts) and the jury returned with a verdict of guilty of the count on the indictment.

Ground 1: admissibility of Mr Ballard's opinion evidence

1. Ground 1 of the appeal is a challenge to the decision to admit Mr Ballard's evidence. That decision was made on the basis of:

• Mr Ballard's statement;
• evidence given by Mr Ballard in the committal proceedings; and
• evidence given by Mr Ballard on the voir dire prior to the commencement of the trial. As at trial, the challenge in this Court is limited to the admission of the evidence of Mr Ballard's opinion as to the quantity of methylamphetamine manufactured. Similarly, the bases for the challenge in this Court are the same as those at trial and extracted above at [46].

1. It will be apparent from what I have said above that the second stated basis for objection to the opinion was not properly directed to admissibility, but to whether the opinion ought to be given weight or accepted. It was not framed as an objection that the Crown did not propose to, or would not be able to, prove that the whole of the content of the vessels was the by-product of methylamphetamine manufacture, or that three separate batches had been produced (although the Crown might have had difficulty in identifying such evidence). The objection as taken was directed to the truth or otherwise of those facts. It was directed to whether the assumption that the whole of the liquid in the containers was the waste product of methylamphetamine, and whether the assumption that at least three batches of the drug had been produced, were in fact proved. It may be that the evidence did not meet the more exacting requirements for admissibility that Heydon J would impose. At the time admissibility was under consideration, the Crown would not have been able to point to evidence that supported the assumption that the whole of the liquids in the beer and the buckets was the waste product of drug manufacture, without contamination from other sources.
2. However, Mr Ballard's reasoning process was fully exposed, with the result that, at trial, the jury would be able to evaluate the validity of his conclusion from an examination of the reasoning process.
3. It is also of significance that the assumed fact (to repeat, that the entirety of the liquids in the beer keg and the buckets was the waste product of methylamphetamine manufacture) was not, properly analysed, of the kind that could be said to have been proved or not proved. As events in the trial later demonstrated, the issue was not whether the whole of the liquids were waste product, but the extent (if any) to which there may have been additions to the waste product. As a factual matter, it was never seriously in issue that the liquids did represent waste product; the issue was the extent to which Mr Ballard's opinion as to quantity was valid.
4. The first stated basis for objection does go properly to the question of admissibility. The objection, as framed, appears to accept that the first Dasreef criterion for admissibility (that the witness has specialised knowledge) was satisfied. What it appears to question is whether the second criterion was satisfied, that is whether the opinion expressed was based upon Mr Ballard's specialised knowledge. No clear objection based on the third criterion, exposure of the reasoning process, was articulated, although, as will be seen below, there were aspects of the argument that did venture into that territory.
5. It was expressly conceded that Mr Ballard's academic qualifications as a forensic chemist were not in issue. It was accepted that, based on his qualifications, he could express an opinion that the beer keg had been used in the manufacture of methylamphetamine. What was in issue was whether his assessment of the quantity of the drug was (properly) based on those qualifications - training, study and experience.
6. The evidence met the admissibility requirements stated in Dasreef.
7. I would reject Ground 1 of the appeal.

Ground 2: unreasonable verdict

1. The basis upon which this Court is to deal with a ground of appeal that asserts that the verdict was unreasonable or unsupportable on the evidence has been laid down by the High Court on a number of occasions: see M v The Queen (1994) 181 CLR 487; [1994] HCA 63; MFA v The Queen (2002) 213 CLR 606; [2002] HCA 53; SKA v The Queen (2011) 243 CLR 400; [2011] HCA 13. They were recently reviewed by Bathurst CJ in Dickson v R [2017] NSWCCA 78 as follows: "84 The principles on which a court will set aside a verdict as unreasonable are well established. In SKA v The Queen (2011) 243 CLR 400; [2011] HCA 13 at [11]-[14], the Court stated the approach to be adopted was that laid down in M v The Queen (1994) 181 CLR 487; [1994] HCA 63 at 492-494, namely that the Court is required to make its own 'independent assessment of the evidence'. If after taking into account the primary responsibility of the jury in determining the question of guilt or innocence and the benefit of the jury having seen or heard the evidence, the Court is left in doubt as to the reasonableness of the verdict, the verdict should be set aside. In M supra the Court also stated (at 494) that '[i]n most cases a doubt experienced by an appellate court will be a doubt which a jury ought also to have experienced' and '[i]t is only where a jury's advantage in seeing and hearing the evidence is capable of resolving a doubt … that the court may conclude that no miscarriage of justice occurred': see also MFA v The Queen (2002) 213 CLR 608; [2002] HCA 53 at [59]. 85 As was pointed out by Hayne J in Libke v The Queen (2007) 230 CLR 559; [2007] HCA 30 at [113] (Gleeson CJ and Heydon J agreeing), for a verdict to be unreasonable it is not enough that a review of the evidence shows only that it was possible for a jury to reach a different conclusion. However, for a Court to conclude there was no miscarriage, it is not sufficient that there was evidence on which a jury could convict. If after giving full weight to the primacy of the jury, the Court is left in reasonable doubt as to the verdict, it is only where the jury's advantage in seeing and hearing the evidence is capable of resolving the doubt that the Court can conclude that there was no miscarriage of justice. 86 In considering the issue in a case such as the present where the Crown relies on circumstantial evidence, it is important to bear in mind that the task of the appellate court is to consider and weigh all the circumstances in considering and deciding whether there is an inference consistent with innocence reasonably open on the evidence. The evidence is not to be looked at in a piecemeal fashion: R v Baden-Clay (2016) 90 ALJR 1013; [2016] HCA 35 at [46]-[48]."
2. Although this ground also depended upon the opinion evidence, it must be determined on the basis of the evidence adduced in the trial. The question now in issue is whether, on the basis of the properly admitted opinion evidence, that is, Mr Ballard's oral evidence, it was open to the jury to accept that the quantity of methylamphetamine manufactured was not less than 1 kilogram.
3. Mr Ballard gave lengthy evidence in chief, explaining to the jury the process of manufacture of methylamphetamine, what had been observed and seized at the premises, and the analysis of the liquid he considered to be the waste product of three separate instances of methylamphetamine manufacture. None of this is presently in contention. Specifically, as I have said more than once, Mr Ballard's opinion that methylamphetamine manufacture had taken place at the premises is not now in issue.
4. As to the quantity of methylamphetamine produced, it is necessary to set out in some detail his evidence.
5. In evidence in chief he stated and explained his opinion that the methylamphetamine manufactured exceeded 1 kilogram. He said that was because of the quantity of waste product and its chemical makeup. He said that the sour cream bucket contained 7.7 kilograms of what he determined to be waste product, and "that amount of waste would be easily generated from say 500 grams … of methylamphetamine manufactured". He then said that that amount of waste would be consistent with the manufacture of "at least 500 grams" of methylamphetamine. He stated a similar opinion in relation to the contents of the "Lafarge" bucket.
6. Mr Ballard was very effectively cross-examined on behalf of the appellant. With respect to the quantity of methylamphetamine manufactured, he agreed that there was no "specific scientific analysis" from which he could calculate, by reference to the waste material, the quantity of methylamphetamine that had been manufactured. He agreed that he had formed his opinion by reference to the nature and size of the beer keg, and features of the waste product that had been revealed by scientific analysis. He said that the keg alone was capable of production of "at least a kilogram up to several kilograms". He agreed also that the keg could be used to produce smaller amounts of methylamphetamine, but added that that would be less than "ideal", and would be less efficient because of the large internal volume of the keg, and the smaller amount of material contained in it. He agreed that he had no way of knowing the state of the buckets before the waste material was added to them.
7. The most telling part of the cross-examination concerned the possibility that the content of the containers, which he had (as he later conceded) treated as all waste product, might have been contaminated or diluted by some other substance or substances. He could not exclude the possibility that the content included other components that had nothing to do with methylamphetamine manufacture. He conceded that, if the actual waste product was less than the liquid in the containers, that would affect his calculations of the quantity of methylamphetamine manufactured; by how much would depend upon how much less waste there had been. He said that if the quantity of waste product was less than the quantity of liquid in the containers by only "several kilos", or perhaps even by half, he would still have arrived at the opinion that in excess of 1 kilogram of methylamphetamine had been produced.
8. Mr Ballard was specifically asked about the potential effect of additives such as bleach or caustic soda. He agreed that if such substances had been added to the waste product, it would have increased its volume.
9. At that point in the cross-examination the court adjourned for the day. The next morning Mr Ballard advised counsel that, in the light of the cross-examination, he had reviewed his notes and revised his opinion. He said that he had realised that there was a level of chloride ions in the liquid that may have impacted on his assessment of quantity. He was therefore further questioned by the trial advocate in the presence of the jury. He said that there was "a reasonably high level of what appears to be chloride ions present in the waste material in the keg and in both buckets".
10. Mr Ballard said that one possible explanation for the presence of the chloride ions was the addition of a substance high in chloride ions, such as bleach or salt. The level of chloride ions was more than would have been expected from the methylamphetamine manufacturing process that he had earlier described.
11. The transcript then records the following evidence: "Q. What effect, if any, does this have on your opinion about the quantity of methylamphetamine that was likely to be produced, taking into account the volume of waste product you saw? A. Considering the total volume of waste product - well, if you just look at the keg and the two buckets in front of it, a total of 44 kilograms of waste, which is a significant quantity of waste. I can't say how much of that was potentially something that was added to it, but that is still consistent - with all of the other components, still consistent with waste from the manufacture process, still consistent with what I've seen many, many times over the years. I still believe it to be the waste from a manufacturing process and likely to still be from the production of more than a kilogram in total of methylamphetamine. But my opinion in that regard is not as strong as it was yesterday as far as the greater than a kilogram - as it was yesterday without the further evidence. Q. While we're on the subject, I'll ask you some about that. Your evidence was actually that from the keg alone you'd expect at least a kilogram. Is that right? A. That's right. Q. Are you still of that opinion? A. I am still of that opinion, given the size of the keg and what I've seen in the past - my experience with it - that vessels of that size are of use in the manufacture of kilogram quantities. Q. … But at this point you're still of that opinion, that at least a kilogram is likely to have been produced from that volume of waste that you saw in the keg. A. As I say, I believe so, given the amount of waste. Even if there was only half - half of that was waste, half of it was something added, that's still a total of 22 kilograms - or in the keg around- Q. I'll go straight to that. I was going to perhaps take a little bit more time, but I'll go straight to that piece of evidence. You were asked, 'I imagine you say it would be a little lower; probably makes no difference to you at all if it's only a matter of a hundred grams or so?' and your answer was, 'If it were only a matter of several kilos or perhaps even half the weight, it would still lead me to form the same opinion.' A. Yes. Q. Do you stick by that answer that you gave? A. Yes. Q. In relation to the buckets, you said that you thought that that was indicative of at least the production of 500 grams. A. Yes. Q. Are you still of that opinion? A. Again because I now believe that there is the possibility of something having been added to it, I'm not as strong in my opinion of that. If you had half of the amount in the buckets - say around 4 kilos - then 4 kilos, I may, to be on the conservative side, round that down to, say, half of that. Maybe not 500 grams, maybe down to around 250 grams. Q. So 250 in each. 250 from each bucket? A. Yes, if we're looking at a 50% mix." (italics added)
12. In cross-examination Mr Ballard agreed that he now thought it likely that something had been added to the liquid after the completion of the manufacturing process, and that that was something that contained chloride ions.
13. The following evidence was given in cross-examination: "Q. The result of your reconsidering your notes overnight is that you're now not confident as to whether or not the waste you saw was just reaction waste or waste that has had something added to it. Is that right? A. That's right. Q. If it were the latter - that is, if something has been added to it - you're not able to say how much. A. No. Q. You've told the jury that you still in your opinion think that half of the total quantity of 44 kilos would be sufficient for more than a kilo of methamphetamine. A. Yes. Q. You used this expression, though: your opinion in that regard is not as strong as it was yesterday. A. That's right. Q. Put simply, the further away from the 44 kilogram total you come, the smaller the quantity of methamphetamine that was produced. A. That's right. Q. You say you believe, at half that level, more than a kilogram is still possible. A. Yes. Q. But is one to take your evidence about your opinion not being as strong that you couldn't be as certain as you perhaps were when you thinking of 44 kilograms? A. Yes. Q. Indeed, it's possible it may be something less than a kilogram if the waste has been added to by other means? A. There is that possibility." (italics added)
14. The last answer was unqualified. Although Mr Ballard was re-examined, no attempt was made to explore that answer.

Consideration

1. Mr Ballard's evidence was (until the very last question and answer) consistently that, even after the revision of his opinion in the light of his recognition of the significance of the presence of chloride ions, he considered that the quantity of methylamphetamine produced exceeded 1 kilogram. The last answer, however, admitted of a possibility that that was not so.
2. It is trite, in a criminal prosecution, that every element of the offence charged must be proved beyond reasonable doubt. If there is a reasonable possibility that one element has not been proved to the requisite degree, the prosecution case must fail. That methylamphetamine in a quantity not less than 1 kilogram had been produced was an essential element of the Crown case on the charge on the indictment. It is therefore inescapable that, in the light of Mr Ballard's acceptance of the possibility that less than 1 kilogram of methylamphetamine had been produced, the prosecution case on that element must fail. The appellant is entitled to an acquittal on the count on which he was indicted.
3. That, however, is not the end of the matter. Section 7(2) of the Criminal Appeal Act 1912 (NSW) provides as follows: "Where an appellant has been convicted of an offence, and the jury could on the indictment have found the appellant guilty of some other offence, and on the finding of the jury it appears to the court that the jury must have been satisfied of facts which proved the appellant guilty of that other offence, the court may, instead of allowing or dismissing the appeal, substitute for the verdict found by the jury a verdict of guilty of that other offence, and pass such sentence in substitution for the sentence passed at the trial as may be warranted in law for that other offence, not being a sentence of greater severity."
4. That calls into play the two alternative offences which were left to the jury. The first was manufacture of not less than the commercial quantity (250 grams). The second was of the bare offence of manufacturing (an unspecified quantity) of methylamphetamine.
5. There is no question that it is open to this Court to substitute a verdict of guilty of the bare offence. The question which arises is whether it is also open to this Court to substitute a verdict of guilty of the intermediate offence, manufacture of not less than the commercial quantity. I have concluded that it is. Mr Ballard's concession was that there was a possibility that something less than 1 kilogram of the drug had been manufactured. He was not asked, and gave no evidence, about reduction of the quantity to less than 250 grams. In my opinion, having regard to the whole of his evidence, and giving full weight to his concession, the jury must have been satisfied of facts that proved the appellant guilty of manufacturing not less than 250 grams of the drug. I propose, therefore, that the verdict of guilty of manufacturing not less than the large commercial quantity be set aside, and that this Court substitute a verdict of guilty of manufacturing not less than the commercial quantity. That, of course, raises the question of sentence. The sentence must be adjusted to take account of the lesser maximum penalty provided.
6. Because there was no application for leave to appeal against sentence, this Court was provided with no material relevant to sentence. It will be necessary to remit the matter to the District Court for re-sentencing.
7. The orders I propose are: 1. Appeal against conviction of manufacturing not less than the large commercial quantity of methylamphetamine allowed; 2. The verdict of guilty of that offence be set aside; 3. In lieu thereof, pursuant to s 7 of the Criminal Appeal Act 1912 (NSW), the appellant be convicted of manufacturing not less than the commercial quantity of methylamphetamine; 4. Matter remitted to the District Court for sentencing for that offence.
8. WALTON J: I agree with the reasons for judgment and the orders proposed by Simpson JA.
9. BUTTON J: I agree with Simpson JA.

Amendments 21 August 2017 - Corrected representation DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 21 August 2017