38 Similarly, at the end of each report, Mr Curtin expresses his conclusions in terms that his " ... analysis indicates there was some other source of funding to account for the cash deposits and payments" detected by him during the period 1 January 1999 to 30 June 2002.
39 That statement by Mr Curtin not only involves the drawing by him of an inference, but also the expression by him of an opinion which is essentially a matter for the jury. In fact, if the jury were to accept Mr Curtin's analysis, it would accept that Mr Curtin had, on the information available to him, and by using the accounting criteria adopted by him, identified cash payments and cash deposits which were not sourced from cash withdrawals, or from other known sources of income. What conclusion is to be derived from such evidence is essentially a matter for the jury. I raised this matter in argument with counsel. Mr Leckie agreed that the conclusions of Mr Curtin, as thus expressed, were inadmissible. That concession by Mr Leckie is correct. I would not permit Mr Curtin to give evidence of his conclusions in the form in which they are now expressed.
40 The third rider is similar and relates to the use by Mr Curtin of the term "unsourced" in respect of cash deposits and cash payments for which he has not been able to identify any source, either from the information available to him, or by application by him of the criteria and assumptions which he as an accountant developed. In essence, the "unsourced" transactions are those which he has not been able to eliminate as being sourced from funds, based on the information available to him, and based on the application of the criteria and assumptions identified by him in his reports. The unqualified use by Curtin of the word "unsourced" expresses a conclusion or inference by the accountant from that exercise. It is not an inference or conclusion which he is permitted as an expert to express. The reaching of that conclusion is a matter for the jury.
Admissibility of evidence - discretion
41 The second basis upon which the accused seek to have the evidence of Mr Curtin excluded is by an exercise of the judicial discretion. In each case it is submitted that the probative value of Mr Curtin's evidence is limited, and that it is significantly outweighed by the unfair prejudice which would be occasioned to each accused should Mr Curtin be permitted to give that evidence.[12]
42 Different submissions were made on this aspect of the case by counsel on behalf of each of the accused. However, the submissions did contain some points in common which I shall consider before turning to the submissions made on behalf of each accused.
43 The starting point for the submission on behalf of each of the accused was that the probative value of the evidence of Mr Curtin was considerably limited. First, each of the reports contains a statement of the "inherent limitations" of the financial analysis undertaken by Mr Curtin. Those limitations included that the information provided was restricted to detected documented transactions; the records of each family unit are incomplete; and there was an absence of information concerning cash deposits, cash payments and cash withdrawals. In respect of this third aspect, the source of cash deposits and cash payments have not been provided, and there has been no information as to the application of cash withdrawals. It is because of those limitations that Mr Curtin has had to develop his assumptions. Counsel for the accused have submitted that the assumptions now identified in the expert's reports are themselves "fragile". Some of them, self-evidently, operate arbitrarily and artificially. For example, the assumption that an earlier cash withdrawal is not off-set at all against a subsequent cash payment is artificial and prone to error. Thus the nature of the criteria adopted by Curtin means that the figure ultimately arrived at by him in each case is of dubious validity.
44 It is clear that the exercise undertaken by Mr Curtin has its limitations, deriving from the limited amount of information available to him. Further, it is evident that the accuracy and validity of Mr Curtin's analysis depends upon the appropriateness and validity of the criteria and assumptions utilised by him. Nonetheless, despite those limitations, the evidence does potentially have significant probative value. As I have already stated, a number of cash deposits and cash payments, characterised by Curtin as "unsourced", are unaffected by the assumptions and criteria which he has adopted. In other words, in respect of those transactions, there is no available cash withdrawal, or other source of income, which could conceivably account for those transactions. Thus in each case the report of Mr Curtin does identify a significant amount of cash transactions which, on their face, do not seem to be affected by the limitations to which Mr Curtin has adverted. Further, the limitations of information available to Mr Curtin potentially can work in both directions. It is true that the limitations on information available to Mr Curtin may mean that he is not in possession of information which might account for otherwise unsourced cash payments or cash deposits. On the other hand the same limitations mean that he may not have identified a significant amount of unsourced cash payments.
45 On the matters which were revealed on the voir dire, and on the basis of matters put in cross-examination, I do not accept that the probative worth of Mr Curtin's evidence is slight or insignificant by virtue of the limitations and assumptions specified in his report. Ultimately an assessment of the weight of the evidence is a matter for the jury. However I do not conclude that the evidence can only be characterised as having slight probative worth. Further and importantly the evidence is directed to a central issue in the case. The Crown case against the accused is based on an allegation of a significant amount of trafficking in heroin over a three and a half year period. On the Crown case significant amounts of payments in cash were made to one or more of the accused Cox, Sadler and Ian Ferguson. In that context the identification by the accountant of cash payments and cash deposits, which are not accounted for by information available to him, or by cash withdrawals from the accounts of the accused, is particularly relevant.
46 Each of the accused has also submitted that the evidence of Curtin, if admitted, would be unfairly prejudicial to that accused. Two common arguments were made on behalf of each of the accused. First, it was submitted that the effect of the evidence of Mr Curtin was to reverse the onus of proof on each accused. Counsel referred to the evidence of Curtin that he did not off-set an earlier cash withdrawal from a bank account of an accused against a subsequent cash deposit into the same bank account. It was submitted that by doing so Curtin did not off-set amounts which, in reality, may well have been related transactions. By not off-setting those two amounts Curtin in effect cast an onus on the accused to prove that the cash deposit was funded from the proceeds of the prior cash withdrawal. A similar point was made in respect or Curtin's evidence that he did not off-set an earlier cash withdrawal against a subsequent larger cash payment. Again, in reality, an earlier cash withdrawal, in those circumstances, might have been used to partially account for the subsequent cash payment.
47 While the methodology of the accountant may well be open to scrutiny and indeed criticism, nonetheless I do not accept that his methodology does involve a reversal of an onus of proof as contended for by the accused. The effect of the accountant's evidence is no more than that, applying his methodology and criteria, two transactions are not off-set or related. Such a proposition by the accountant does not cast any onus of proof on the accused. The adoption of those criterion means no more than that, as an accountant, Curtin did not apply criteria which would permit the off-setting of the two transactions. However, essentially it is a matter for the jury whether they are satisfied beyond reasonable doubt that one transaction is not off-set against another. The jury may or may not accept the methodology of the accountant. Indeed they may accept his methodology but not be satisfied beyond reasonable doubt that two transactions are not related. However in any event the adoption of the methodology and assumptions by the accountant is no more than that; it does not, contrary to the submissions of the accused, reverse any onus of proof in the case.
48 The main aspect of prejudice contended for by the accused is that there is a risk that a jury will seize on the "bottom line" figure of Curtin in each of his reports. Thus the jury may take the view, particularly in a long case, that the figure derived by Curtin is a figure arrived at by an experienced and expert accountant, and thus invest it with undue weight. It was submitted that this risk is particularly significant in this case because of the similarity of the criteria relied on by Curtin to the type of assumptions a jury might itself make in determining whether particular transactions are related or to be off-set.
49 There is, of course, always a risk that a jury, in any case, might be beguiled by any expert, and tend to give the views of that witness excessive weight simply because of the status of the witness as an expert. However, as in any case, I consider that such a risk can be appropriately counteracted by judicial direction, both during the trial, and in final directions, as to how the jury is to scrutinise and assess the evidence of the expert for itself.
50 In this case, the expert has now articulated each of the limitations to his report, and each of the assumptions and criteria adopted by him in determining whether or not particular transactions are "unsourced". The jury will be instructed that they are to take into account all of the limitations specified by the accountant, and any other limitations revealed in evidence. Further, the jury will be instructed that it is for them to critically analyse and assess the criteria and assumptions relied upon by the expert. Further and importantly, if the evidence of Mr Curtin is to be admitted, it will be on the basis that the witness is not expressing views based on assumptions as to the spending habits of ordinary people. The evidence would be admitted on the basis that Curtin, using his expertise and experience, was analysing the transactions as an accounting exercise. In other words, Mr Curtin would not be permitted to express views which might usurp the role of the jury. Rather the evidence of Mr Curtin would be admitted to provide guidance to the jury as to how an accountant might approach the exercise. Ultimately, however, the jury will be directed that it is a matter for them to determine in each case whether or not a particular cash transaction has been shown not to be derived from a known source of funds of each accused.
51 I now turn to consider individually the submissions made on behalf of each accused as to the prejudice which they might suffer should the evidence of Curtin be admitted.
Cox - discretion
52 Mr Young submitted that there were factors particular to the case of Cox which rendered the evidence of Mr Curtin of little probative value. He submitted that, on the other hand, there was significant prejudice in having the evidence admitted against his client.
53 Mr Young submitted that, when properly scrutinised, the evidence of Mr Curtin was of little probative worth in the case against Mr Cox. First, he submitted that the "bottom line" figure of $31,000 betterment assessed by Mr Curtin against Mr Cox is fragile and of little probative worth. He relied on matters which I have already discussed above, such as the limitations on the material available to Curtin and the nature of the assumptions and criteria relied upon by Curtin. Further, in the case of Cox he also pointed out that Curtin has not taken into account other potential sources of cash. In particular he has not taken into account the fact that Cox, since early 2000, conducted an investigation business ("Selection Investigations") from which he might have derived cash income. Further the analysis of Curtin ignores the "cash out" component of payments made by Cox by credit card to supermarkets. All of those payments were characterised as "household expenses" by Curtin, not taking into account the fact that they may have also resulted in "cash out" to the customer.
54 In addition Mr Young submitted that the evidence was of little probative worth for the following reasons: