Q. Because obviously if it was brown when it was harvested, you can't draw any conclusion from it being found brown later, can you?
A. I'm not sure.
Q. You've indicated to his Honour and the jury that there were cannabis plants shown in the photos that were brown in colour in the ground, haven't you?
A. That's right, yes.
Q. The first variable, I'd suggest to you, is the colour at harvest; what do you say about that?
A. Sorry, in what respect?
Q. The colour at harvest obviously needs to be taken into account, doesn't it?
A. Normally, yes.
Q. You had no information as to what colour any of this material was when harvested, did you?
A. Oh, no." (T234-5).
19 The cross examination later continued:
"Q. The second feature, I'd suggest to you, that may affect the appearance of material is the manner in which it was processed; what do you say about that?
A. Yes.
Q. Because it's obviously the case, isn't it, that if material is dried in the sunlight, it's going to fade?
A. That's correct, yes.
Q. And it's going to have a different appearance, isn't it, to material which has been dried through some sort of drying process out of sunlight; correct?
A. I'm not sure.
Q. Sunlight fades, doesn't it?
A. Normally, yes.
Q. And things that are out of the sun are not faded by sunlight, are they?
A. Normally not.
Q. So what I'm suggesting to you is the manner in which a thing is dried will affect its colour at the end of the drying process; what do you say about that?
A. It's a possibility.
Q. It's more than that, isn't it; it's an inevitability?
A. I'm not sure.
Q. What I'd suggest to you is that something which is dried in the sun will have a much lighter colour than something which is dried by some other process; what do you say about that?
A. That's a possibility, yes.
Q. It's an inevitability, I'm putting to you?
A. I'm not sure." (T235-6).
20 The cross examination continued:
"Q. Do you agree with that, you have got no information obviously about its condition on harvest, have you?
A. I'm only going on my experience as a person who identifies cannabis leaf.
Q. Please answer apply (sic) question: You have got no information about the condition of the leaf material when harvested, have you?
A. No.
Q. And similarly you have got no information about the process which it was subjected to after harvest, have you?
A. No, I haven't.
Q. The storage conditions after harvest are the third variable obviously; correct?
A. Yes.
Q. And there are a range of manners in which the storage conditions can affect the appearance of not only cannabis leaf but plant material; do you agree with that?
A. Yes.
Q. For example, in the light, whether it's in the sunlight or whether it's in the dark or in between; do you agree with that one?
A. Oh, yes.
Q. Whether it's in the open air or whether it's in an airtight container?
A. Yes.
Q. The temperature?
A. Yes.
Q. The humidity?
A. Yes.
Q. Possible interference by vermin?
A. Yes.
Q. In relation to the material here what you're able to do is make observations of the appearance of that material on the day you got there; correct?
A. That's right.
Q. You're not able to say what had happened to it from time of harvest to the time you got there, are you?
A. Oh, no." (T236-7).
21 It was an essential element of the Crown case that the drug be shown to have been harvested and in the possession of the appellant prior to his departure for overseas in May 2001. His Honour directed the jury thus:
"So possession can be whittled down to this. The prosecution must prove beyond reasonable doubt that the accused did place the drugs in the position where they were as at 4 September 2001 when the police came and that would be the physical element of possession and the accused intended to have control and dominion over those drugs to the exclusion of all other people and that would be the mental element of possession."
22 There was no direct evidence of possession by the appellant and it was the Crown case that, by reason of the harvest of the cannabis at a time before the appellant departed, the jury would be satisfied that he had been so in possession. The only evidence that the plants must have been harvested before the departure date was the opinion of Mr Wassell.
23 As the evidence showed, his claim to expertise was based solely upon asserted experience. His opinions were inadmissible unless permitted by s 79 of the Evidence Act 1995, namely:
"79. 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."
24 Attention was directed to the discussion in the judgment of Heydon JA (as he then was) in Makita (Australia) Pty Limited v Sproules 2001 52 NSWLR 705 @ 743 where his Honour wrote:
"In short, if evidence tendered as expert opinion evidence is to be admissible, it must be agreed or demonstrated that there is a field of 'specialised knowledge'; there must be an identified aspect of that field in which the witness demonstrates that by reason of specified training, study or experience, the witness has become an expert; the opinion proffered must be 'wholly or substantially based on the witness' expert knowledge'; so far as the opinion is based on facts 'observed' by the expert, they must be identified and admissibly proved by the expert, and so far as the opinion is based on 'assumed' or 'accepted' facts, they must be identified and proved in some other way; it must be established that the facts on which the opinion is based form a proper foundation for it; and the opinion of an expert requires demonstration or examination of the scientific or other intellectual basis of the conclusions reached: that is, 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. If all these matters are not made explicit, it is not possible to be sure whether the opinion is based wholly or substantially on the expert's specialised knowledge. If the court cannot be sure of that, the evidence is strictly speaking not admissible, and, so far as it is admissible, of diminished weight. And an attempt to make the basis of the opinion explicit may reveal that it is not based on specialised expert knowledge, but, to use Gleeson CJ's characterisation of the evidence in HG v The Queen (at 428, 1999 197 CLR 414), on 'a combination of speculation, inference, personal and second-hand views, as to the credibility of the complainant, and a process of reasoning which went well beyond the field of expertise."
25 His Honour's dicta were adverted to in Sydney Wide Distributors Pty Limited v. Red Bull Australia Pty Limited [2002] FCAFC 157. Branson J commented that the approach of Heydon JA seemed a counsel of perfection although when her Honour elaborated her reservations, she noted that the existence of a field of specialised knowledge was something which might be assumed in cases where evidence is adduced without objection. In the present case there was specific objection. We would, however, respectfully agree with her later observation that the use of the word "sure" by Heydon JA should be understood other than in the usual sense of being subjectively certain: Evidence Act, s 142.
26 It is not necessary in the present case to engage in an examination of any differences in these views. The evidence fell far short of demonstrating that Mr Wassell (whose bona fides, we should mention, were not in question) could, by simply looking at cannabis, and in the absence of any information about appearance at the time of harvest, conditions between harvest and storage, the time at which the material was placed into storage, if storage may have affected its appearance and whether conditions varied during storage, establish when harvest had taken place. It is true, of course, that there was no issue about his being able to identify cannabis, but what he lacked by way of experience was assessing the "timetable" within which observable deterioration in plants took place.
27 In the appeal, senior counsel for the Crown submitted:
"… If the view be taken that Mr Wassell had insufficient specialized knowledge with regard to the ageing processes of cannabis leaf in its harvested form, or that his opinion was not reached upon the basis of his specialized knowledge, and that the opinion expressed is properly to be seen as a lay opinion, there is a rational basis for Mr Wassell holding that opinion, namely the condition of the cannabis leaf and the circumstances in which it was found measured against his years of experience as an agronomist engaged upon the inspection of plants. …. In those circumstances, section 78 of the Evidence Act, 1995 applies."
28 Section 78 provides:
"78. The opinion rule does not apply to evidence of an opinion expressed by a person if:
(a) the opinion is based on what the person saw, heard or otherwise perceived about a matter or event, and
(b) evidence of the opinion is necessary to obtain an adequate account or understanding of the person's perception of the matter or event."
29 We would reject that submission. The only matter or event was the viewing and identification of the cannabis. The opinion evidence was an assertion of something said to have happened beforehand (harvest) and specifying the time which must have elapsed between the harvest and the viewing, a progression which Mr Wassell did not purport to see, hear, or otherwise perceive.
30 Ground 1 is made out.
31 It is significant in dealing with ground 2 to have regard to the evidence of just what Mr Wassell's experience was. As earlier stated, his formal training had been focussed upon identification and he had had no reference to relevant literature. His experience did not include "timetabling" deterioration of cannabis from harvest until a time of inspection. Further he conceded, inter alia, that any opinion would require knowledge of the state (appearance) of the plant at the time of harvest and plainly evidence of that sort had not been, and now cannot be, forthcoming.
32 It is of interest to note his candour about the novelty (as far as he was concerned) of being asked about this issue:
"Q. Mr Wassell, would it be fair to say that the evidence you have given today is evidence of a type which you have never given in any court before, that is, relating to the age of cannabis leaf?
A. No, I haven't done it before.
Q. In cases other than this case?
A. Yes.
Q. Well, could I suggest to you that before giving evidence of this type, you need to undertake proper experiments to check the accuracy of your conclusions. What do you say about that?
A. Possibly. " (T248).
33 The concession by Mr Wassell demonstrates that he is unable from experience to qualify himself to give the opinions which were led from him in evidence. Ground 2 should be upheld.
34 We turn to ground 3. We have already set out his Honour's direction that the Crown had to prove possession by the placing of the drugs in the positions found, before 4 September 2001. The requirements of proof of the Crown case needed to go further than that. On the admitted facts of the appellant's absence, it needed to be proved as an indispensable link in any chain of reasoning in this circumstantial case that the cannabis was harvested before 15 May 2001. There was no other evidence from which such an inference could be drawn without proof of that fact. His Honour was required to give a direction so that the jury would understand that they could not return a verdict of guilty unless they were satisfied beyond reasonable doubt that the cannabis had been harvested before the appellant left for overseas. No such direction was given: Shepherd v The Queen 1991 70 CLR 573.
35 It is conceded on behalf of the appellant that no application to withdraw the evidence of Mr Wassell such as is contemplated by ground 5 was made at trial. Rule 4 therefore applies. In this respect the Court was referred to BRS v The Queen 1997 191 CLR 275, in particular the expressions of Toohey and Gaudron JJ concerning the granting of leave pursuant to r 4 where a trial has miscarried for want of proper direction and a verdict of not guilty may have followed.
36 Counsel were unable to refer to any authority where evidence, once admitted, had been withdrawn by the trial judge from the jury other than in cases where the evidence was evidence of identification. In that regard the Court was referred to R v Tugaga 1994 74 A Crim R 190. Although not in the context of a jury trial it might be noted that Weinberg and Dowsett JJ in Sydney Distributors @ par 87 made these observations:
"The use of the phrase 'strictly speaking' in the last sentence should not be overlooked. It may well be correct to say that such evidence is not strictly admissible unless it is shown to have all of the qualities discussed by Heydon JA. However many of those qualifies involve questions of degree, requiring the exercise of judgment. For this reason it would be very rare indeed for a court at first instance to reach a decision as to whether tendered expert evidence satisfied all of his Honour's requirements before receiving it as evidence in the proceedings. More commonly, once the witness's claim to expertise is made out and the relevance and admissibility of opinion evidence demonstrated, such evidence is received. The various qualities described by Heydon JA are then assessed in the course of determining the weight to be given to the evidence. There will be cases in which it would be technically correct to rule, at the end of the trial, that the evidence in question was not admissible because it lacked one or other of those qualities, but there would be little utility in so doing. It would probably lead to further difficulties in the appellate process."
37 In the light of grounds 1, 2 and 3 being made out it is unnecessary in this case to determine whether the power of a trial to withdraw evidence does extend beyond evidence of identification and we would reserve that question until an occasion when it is necessary so to decide and the matter can be considered in depth.
38 As we have recited, ground 4 is expressed in terms of the "tendency evidence" of Mr Sharp. The thrust of the evidence was that he had seen the applicant in areas of the property on which cannabis plants were growing, of the presence of which he must have been aware. If his evidence was tendency evidence, notice pursuant to s 97 of the Evidence Act was required. None was given. His Honour exercised his power pursuant to s 100 to dispense with such requirement (T167). However, his Honour had raised with counsel whether the evidence may not have been admissible simply on credit, that is to contradict the statements by the appellant to police that he had no knowledge of any cannabis on the property. Although the matter is not altogether free from confusion, it does appear that the evidence was admitted on this basis.
39 However, if the evidence was admitted limited to an issue of credit, the jury should have been directed as to the limited use they could make of it. They were not so directed.
40 What his Honour did say in his charge to the jury was:
"……. He (Mr Sharp) thought round about 1998 although he was not too sure of the dates, that he said that he, from a distance of about twenty-five metres, he had seen about thirty to fifty cannabis plants of up to about five feet tall I think he said, which were tied down and that he saw the accused right there amongst those plants but he could not see what he was doing which again the prosecution relies upon as showing that the accused did have an interest in cannabis."
41 The use of the expression "an interest in cannabis" raises a matter of tendency of the appellant. No requisite direction as to limitation on the use of tendency evidence was given.
42 Neither counsel at trial sought redirection. Whatever the status of evidence of Mr Sharp there was no appropriate direction. We would grant leave under r 4 to raise this ground which is made out.
43 Whilst some of the grounds made good by the appellant are such as ordinarily to provoke consideration of ordering a new trial, that is not the case in respect of ground 2 in particular. We were satisfied that, without the evidence of Mr Wassell, it was not open to the jury to find the appellant guilty. The judge should have rejected his evidence and directed a verdict of not guilty.
44 For the foregoing reasons the orders were made at the conclusion of the hearing of the appeal.