- In Campbell v Campbell  NSWSC 784 Sackar J said:
 In Watson v Foxman (1995) 49 NSWLR 315 and 319, McLelland CJ in Eq made the following remarks:
…human memory of what was said in a conversation is fallible for a variety of reasons, and ordinarily the degree of fallibility increases with the passage of time, particularly where disputes or litigation intervene, and the processes of memory are overlaid, often subconsciously, by perceptions or self-interest as well as conscious consideration of what should have been said or could have been said. All too often what is actually remembered is little more than an impression from which plausible details are then, again often subconsciously, constructed. All this is a matter of ordinary human experience.
 Whilst a trial judge is entitled to make observations relating to the demeanour of certain witnesses, it is a notoriously crude and inaccurate methodology. Its defects have been exposed on numerous occasions.
 It is true, as McHugh J has pointed out, that for a very long time judges in appellate courts have given as a reason for appellate deference to the decision of a trial judge, the assessment of the appearance of witnesses as they give their testimony that is possible at trial and normally impossible in an appellate court. However, it is equally true that, for almost as long, other judges have cautioned against the dangers of too readily drawing conclusions about truthfulness and reliability solely or mainly from the appearance of witnesses. Thus, in 1924 Atkin LJ observed in Societe d’Avances Commerciales (Societe Anonyme Egyptienne) v Merchants Marine Insurance Co (The “Palitana”):
“… I think that an ounce of intrinsic merit or demerit in the evidence, that is to say, the value of the comparison of evidence with known facts, is worth pounds of demeanour.”
 Further, in recent years, judges have become more aware of scientific research that has cast doubt on the ability of judges (or anyone else) to tell truth from falsehood accurately on the basis of such appearances. Considerations such as these have encouraged judges, both at trial and on appeal, to limit their reliance on the appearances of witnesses and to reason to their conclusions, as far as possible, on the basis of contemporary materials, objectively established facts and the apparent logic of events. This does not eliminate the established principles about witness credibility…
 In the recent decision of McGraddie v McGraddie and another  UKSC 58;  1 WLR 2477, the UK Supreme Court emphasised that, especially in cases where a trial judge is faced with a stark choice between irreconcilable accounts, the credibility of the parties’ testimony, and the trial judge’s assessment of the character of witnesses and the manner in which the witnesses give evidence, is of primary importance. Those observations are particularly relevant to the present case. Similar observations have been made in Australian authorities (Fox v Percy at ; Rosenberg v Percival  HCA 18; (2001) 205 CLR 434 at  per McHugh J and see generally comments in Ritchie’s Uniform Civil Procedure NSW at SCA s 75A.20).
 In Camden v McKenzie  1 Qd R 39 at  Keane JA (as he then was) made the observation that “the rational resolution of an issue involving the credibility of witnesses will require reference to, and analysis of, any evidence independent of the parties which is apt to cast light on the probabilities of the situation.” This remark was cited with approval by Leeming JA (with whom Barrett JA and Tobias AJA agreed) in New South Wales v Hunt (2014) 86 NSWLR 226 at .
 In that case, his Honour was talking of a cause of action founded on s 52 of the Trade Practices Act 1974 (Cth) or s 42 of the Fair Trading Act 1987 (NSW): see the discussion by McDougall J in Harbour Port Consulting v NSW Maritime  NSWSC 813, at  – . However, as McLelland CJ in Eq also pointed out, the views apply to all types of litigation.
 I also remember what was said by Emmett J (as his Honour then was) in Warner v Hung, in the matter of Bellpac Pty Ltd (Receivers and Managers Appointed) (In Liquidation) (No 2)  FCA 1123; (2011) 297 ALR 56, at :
“When proof of any fact is required, the Court must feel an actual persuasion of the occurrence or existence of that fact before it can be found. Mere mechanical comparison of probabilities, independent of any belief in reality, cannot justify the finding of a fact. Actual persuasion is achieved where the affirmative of an allegation is made out to the reasonable satisfaction of the Court. However, reasonable satisfaction is not a state of mind that is attained or established independently of the nature and consequences of the fact to be proved. The seriousness of an allegation made, the inherent unlikelihood of an occurrence of a given description, and the gravity of the consequences flowing from a particular finding are considerations that must affect whether the fact has been proved to the reasonable satisfaction of the Court. Reasonable satisfaction should not be produced by inexact proofs, indefinite testimony or indirect inferences (see Briginshaw v Briginshaw (1938) 60 CLR 336 at 361-2).”
 The credibility of a witness and his, or her, veracity may also be tested by reference to the objective facts proved independently of the evidence given, in particular by reference to the documents in the case, by paying particular regard to his, or her, motives, and to the overall probabilities: Armagas Ltd v Mundogas S.A. (The “Ocean Frost”)  1 Lloyd’s Rep 1, per Robert Goff LJ, at 57. Also see, In the matter of Kit Digital Australia Pty Ltd (in liq)  NSWSC 1547, per Black J, at .
 A court, in cases involving events which occurred long before the litigation, usually prefers to rely upon contemporaneous, or near contemporaneous, documents, which will often provide valuable and, usually, more revealing, information than what may be flawed attempts at recollection of those facts by persons with an interest in the outcome of the litigation: Bathurst Regional Council v Local Government Financial Services Pty Ltd (No 5)  FCA 1200, per Jagot J, at . Greater weight is usually accorded to such documents, as often they provide a safer repository of reliable fact, particularly when it is clear that they have been prepared by a person with no reason to misstate those facts in the documents and where there is no suggestion that the documents are other than genuine: Hughes v St Barbara Mines Ltd [No 4]  WASC 160, per Kenneth Martin J, at .
 The circumstances of this case, make what was written by Tamberlin J in Lake Cumbeline Pty Ltd v Effem Foods Pty Ltd (trading as Uncle Ben’s of Australia) (Federal Court of Australia, Tamberlin J, 29 June 1995, unrep), at 122 – 123 (in a passage cited with approval by the High Court when it upheld his Honour’s decision: Effem Foods Pty Ltd v Lake Cumbeline Pty Ltd  HCA 15; (1999) 161 ALR 599, at ) appropriate to remember:
“[Given the lapse of time] between the events and conversations raised in evidence and the hearing of the evidence before me, the only safe course is to place primary emphasis on the objective factual surrounding material and the inherent commercial probabilities, together with the documentation tendered in evidence. In circumstances where the events took place so long ago, it must be an exceptional witness whose undocumented testimony can be unreservedly relied on. The witnesses in this case unfortunately did not come within that exceptional class. The discussions referred to in evidence were capable of bearing quite opposed meanings depending on subtle differences of nuance and emphasis, and a proper appreciation of the significance of those matters must necessarily be considerably diminished over such a long period of time.”
 Finally, I should mention an article by the former the Chief Judge at Common Law, P McClellan entitled “Who Is Telling the Truth? Psychology, Common Sense and the Law” (2006) 80 ALJ 655, in which he wrote, at 665, quoting a passage from the “Guidelines Relating to Recovered Memories” (2000) of the Australian Psychological Society:
“Memory is a constructive and reconstructive process. What is remembered about an event is shaped by how that event was experienced, by conditions prevailing during attempts to remember, and by events occurring between the experience and the attempted remembering. Memories can be altered, deleted and created by events that occur during and after the time of encoding, during the period of storage, and during any attempts at retrieval.”