12.62 The collateral facts rule at common law provides that, subject to certain exceptions, an answer given by a witness to a question in cross-examination relating solely to a collateral issue (such as credit) is final, and further evidence may not be led on the issue. Section 106 of the uniform Evidence Acts was drafted to replicate and slightly extend the common law exceptions to the collateral facts rule.
12.63 Section 106 lifts the credibility rule and allows the following categories of evidence to be adduced, otherwise than from the witness, if the substance of the evidence has been put to the witness and denied:
the witness’ bias or motive to be untruthful;
the witness’ ability to be aware of matters to which his or her evidence relates;
the making of a prior inconsistent statement by the witness;
the witness’ conviction of an offence, under Australian law or the law of another country; or
the making of a knowingly or recklessly false representation by the witness while under an obligation (imposed under Australian law or the law of another country) to tell the truth.
12.64 In IP 28 and DP 69, the issue of whether the uniform Evidence Acts may have ‘fallen behind the developments achieved at common law’ in this area and become more restrictive than the common law was raised and discussed.
12.65 Some courts have suggested that the list of exceptions to the collateral facts rule under the common law is not closed, and a flexible approach to the rule should be adopted. In Natta v Canham a Full Court of the Federal Court held:
A trial judge should not be precluded from determining in an appropriate case that the matter on which a witness’ credit is tested is sufficiently relevant to that credit as it bears upon issues in the case that such evidence may be admitted.
12.66 The extent to which the common law allows courts the discretion to admit evidence on collateral issues is still open to debate. This is demonstrated by the recent High Court decision in Nicholls v The Queen, in which the majority declined an invitation to redefine the collateral evidence rule to give a broad discretion to admit evidence. The position under the uniform Evidence Acts is, however, clearly limited to the categories of evidence listed in s 106. The concern raised both at common law and under the uniform Evidence Acts is that the restriction of defined categories may prevent the admission of important evidence for reasons of efficiency rather than fairness.
12.67 In Nicholls, McHugh J made a number of comments regarding how the collateral evidence rule should be viewed. While made in the course of discussing the common law rule, his Honour’s views are relevant to whether s 106 should be amended. He pointed to the pragmatic origin of the rule ‘as a rule of convenience—a rule for the management of cases—rather than a fixed rule or principle’ and continued:
The finality rule is important to the efficient conduct of litigation. Without it, the principal issues in trials would sometimes become overwhelmed by charge and counter-charge remote from the cause of action being litigated. In many cases, the finality rule also protects witnesses from having to defend themselves against discreditable allegations that are peripheral to the issues. But the common law should not have any a priori categories concerning the cases where the collateral evidence rule should or should not be relaxed. It should be regarded as a flexible rule of convenience that can and should be relaxed when the interests of justice require its relaxation. Avoiding miscarriages of justice is more important than protecting the efficiency of trials.
12.68 The judge concluded:
[E]vidence disproving a witness’s denials concerning matters of credibility should be regarded as generally admissible if the witness’s credit is inextricably involved with a fact in issue. Consistently with the case management rationale of the finality rule, however, a judge may still reject rebutting evidence where, although inextricably connected with the fact in issue, the time, convenience or expense of admitting the evidence would be unduly disproportionate to its probative force. In such cases, the interests of justice do not require relaxation of the general rule that answers given to collateral matters such as credit are final.
12.69 The Commissions adopted McHugh J’s reasoning in support of its proposal in DP 69 to amend s 106 of the uniform Evidence Acts to ‘include a general discretion to allow proof of collateral matters where the probative value outweighs the disadvantages of time, cost and inefficiency’.
Submissions and consultations
12.70 There is some agreement in submissions and consultations in response to IP 28 that the common law may provide a broader basis on which to admit evidence than s 106; and there was some support for amending s 106 to add a broader discretion to cover situations where the evidence does not fall within the existing exceptions.
12.71 The NSW DPP submits that (as suggested by Associate Professor McNicol) s 106 should be amended to include a general discretion to allow proof of collateral matters where the court is satisfied that the probative value outweighs the disadvantages of time, cost and inefficiency. The Law Council of Australia agrees with this position and comments that:
Such a provision will focus the attention of the court on the substantial issues in the case rather than upon the requirements of a technical rule … It would also importantly give the court a discretion to admit expert evidence relating to the credibility of a witness where it was felt this would usefully contribute to an ultimate determination of the material facts in issue.
12.72 In response to DP 69, the Law Society of NSW and the NSW PDO support the proposal to include a guided discretion to allow rebuttal evidence on matters of credit. Justice French expresses support for the amendment of s 106 to cover the kind of situation that arose in Natta v Canham.
12.73 However, concern is expressed in consultations in Victoria that the broadening of exceptions to the finality rule would add significantly to the time and cost of trials in the civil area, leading to diminished access to justice.
The Commissions’ view
12.74 The Commissions acknowledge concerns that broadening exceptions to the finality rule has the potential to lengthen some trials. However, the Commissions share the view that more flexibility is needed and that avoiding miscarriages of justice is more important than protecting the efficiency of trials. The Commissions believe that concerns about lengthening trials are addressed by the imposition of a leave requirement where the evidence does not fall into one of the existing categories, and by the requirement that the evidence be capable of substantially affecting the credibility of the witness.
12.75 The requirement to obtain leave imports the requirements of s 192 and, in particular, the inclusive list of matters to be considered in s 192(2) which provides:
Without limiting the matters that the court may take into account in deciding whether to give the leave, permission or direction, it is to take into account:
(a) the extent to which to do so would be likely to add unduly to, or to shorten, the length of the hearing; and
(b) the extent to which to do so would be unfair to a party or to a witness; and
(c) the importance of the evidence in relation to which the leave, permission or direction is sought; and
(d) the nature of the proceeding; and
(e) the power (if any) of the court to adjourn the hearing or to make another order or to give a direction in relation to the evidence.
12.76 Adopting a more flexible approach may also reduce the time that can be consumed by arguments as to whether evidence is relevant only to credit or also to facts in issue and as to the precise limits of the current exceptions in subsections (a) to (e).
12.77 Further, as the matters on which evidence is sought to be called under s 106 must be put to the witness in cross-examination, the evidence must have met the requirements of s 103 of being capable of substantially affecting the assessment of the credibility of the witness.
12.78 The Commissions believe the draft amendment to s 106 in Appendix 1 provides the necessary elements of flexibility and control. It also provides a framework for the consideration of case management issues.
 Compare s 104(3)(b) which also includes an express reference to the inability to ‘recall’ matters to which the witness’ evidence relates: see further R v PLV (2001) 51 NSWLR 736. See also S Odgers, Uniform Evidence Law (6th ed, 2004), [1.3.8200]; J Anderson, J Hunter and N Williams, The New Evidence Law: Annotations and Commentary on the Uniform Evidence Acts (2002), [104.35].
Evidence Act 1995 (Cth), ss 43 and 45 impose procedural requirements in relation to cross-examination on a witness’ prior inconsistent statement.
 Compare with Uniform Evidence Acts s 103(2)(a), which does not require the witness’ obligation to tell the truth to be imposed by law.
R v Milat (Unreported, New South Wales Supreme Court, Hunt CJ at CL, 23 April 1996), .
 Australian Law Reform Commission, Review of the Evidence Act 1995, IP 28 (2004), [9.38]–[9.45]; Australian Law Reform Commission, New South Wales Law Reform Commission and Victorian Law Reform Commission, Review of the Uniform Evidence Acts, ALRC DP 69, NSWLRC DP 47, VLRC DP (2005), [11.76]–[11.91]. See also S Odgers, Uniform Evidence Law (6th ed, 2004), [1.3.8120]; S McNicol, ‘Credit, Credibility and Character under the Evidence Acts 1995 (NSW) and (Cth)’ (1999) 23 Criminal Law Journal 339, 350.
Natta v Canham (1991) 104 ALR 143; R v Lawrence  2 Qd R 400; R v Lowrie and Ross  QCA 405; Kurgiel v Mitsubishi Motors Aust Ltd (1990) 54 SASR 125; R v Milat (Unreported, Supreme Court of New South Wales, Hunt CJ at CL, 7 April 1996).
Natta v Canham (1991) 104 ALR 143, 161.
Nicholls v The Queen (2005) 219 CLR 196.
 Ibid, expressly: Gleeson CJ, ; Kirby J,  (referring to the existence of the uniform Evidence Acts, the fact that the uniform Evidence Acts are under consideration in common law jurisdictions, and the inappropriateness of the High Court embarking on a significant task of law reform when adoption of the Acts would solve at least some of the problems); Hayne and Heydon JJ,  (rejecting the suggestion of a discretion).
 Ibid, .
 Ibid, .
 Ibid, .
 See Australian Law Reform Commission, New South Wales Law Reform Commission and Victorian Law Reform Commission, Review of the Uniform Evidence Acts, ALRC DP 69, NSWLRC DP 47, VLRC DP (2005), Proposal 11–5.
 S McNicol, ‘Credit, Credibility and Character under the Evidence Acts 1995 (NSW) and (Cth)’ (1999) 23 Criminal Law Journal 339, 351.
 Queensland Bar Association, Consultation, Brisbane, 9 February 2005; Law Council of Australia, Submission E 32, 4 March 2005.
 Queensland Bar Association, Consultation, Brisbane, 9 February 2005; Law Council of Australia, Submission E 32, 4 March 2005; Director of Public Prosecutions (NSW), Submission E 17, 15 February 2005.
 Director of Public Prosecutions (NSW), Submission E 17, 15 February 2005.
 Law Council of Australia, Submission E 32, 4 March 2005. See discussion below regarding expert evidence.
 New South Wales Public Defenders Office, Submission E 89, 19 September 2005; The Criminal Law Committee and the Litigation Law and Practice Committee of the Law Society of New South Wales, Submission E 103, 22 September 2005.
Natta v Canham (1991) 104 ALR 143. In that case the plaintiff, who claimed damages in relation to a car accident, denied allegations put in cross-examination that she had made statements to a friend that a ‘fake’ accident should be staged to earn some ‘quick money’. The Full Court of the Federal Court held that evidence to contradict the plaintiff’s denials was admissible on the issue of her credibility despite not falling within one of the established exceptions to the collateral facts rule.
 Victorian Law Reform Commission Roundtable, Consultation, Melbourne, 30 August 2005.
 The difficulty of determining whether a matter is relevant to credibility only or also a fact in issue was discussed in Australian Law Reform Commission, New South Wales Law Reform Commission and Victorian Law Reform Commission, Review of the Uniform Evidence Acts, ALRC DP 69, NSWLRC DP 47, VLRC DP (2005), [11.3].
 Ibid, Proposal 11–2.