The Use of Expert Evidence in Court Proceedings and Oppositions

This article first appeared in The Watermark Journal Vol 23 No 3 (September 2006)

Now that the Australia-United States Free Trade Agreement is in force intellectual property disputes and litigation events are expected to increase. In any court proceeding or opposition whether involving patents, trade marks, designs or copyright, one of the most critical aspects of the case is the preparation and filing of evidence.

Good evidence can make a case. However, where insufficient time and effort is devoted to the preparation of evidence, making out a case can be more difficult, and an unsuccessful outcome can often result. Of all the evidence the most important is arguably expert evidence and as the rate of litigation rises the use and importance of expert evidence will increase.

What is Expert Evidence
Under Australian law witnesses other than expert witnesses cannot give opinion evidence, they can only give factual evidence. Factual evidence, as the name suggests, is evidence of a fact, for example, evidence of the number, title and patentee of a patent.

Expert witnesses can give evidence of their opinion provided they have specialised knowledge based on their academic training or experience and their opinion is based on that knowledge. Almost every intellectual property case before the Patent or Trade Marks Office (“Office”) and the courts will involve at least some expert evidence.

Where the expert does not have specialised knowledge, or insufficient basis is given for the opinion, it can be ruled inadmissible (not considered at all) or given lesser weight (considered less important than other evidence, usually that filed by the other party). It is therefore imperative that an appropriately qualified expert is retained and sufficient time and effort devoted to the preparation of their evidence.

Which Expert to Use
Expert evidence is used both in ex parte proceedings and contested proceedings. In contested proceedings both parties will usually retain experts, resulting in conflicting expert evidence being filed. One of, if not the most, important decisions in any case is the choice of expert witness. Two critical factors to consider in choosing an expert are the expert’s impartiality and whether they are qualified in the relevant field.

Impartiality – Each party is likely to have employees who are sufficiently skilled to be considered an expert. Using such an employee may appear attractive, as doing so reduces costs and is likely to result in favourable evidence. However, where the expert is employed by (or otherwise has a relationship with) the party on whose behalf they are giving evidence there is a perception (whether correct or not) that they are not impartial, their evidence is being influenced by the party and thus that their evidence is biased. Evidence which is perceived to be biased will not be given full weight. The most favourable evidence, if not given much weight by the decision maker, is of little value. It is thus preferable to retain an expert witness who has no connection with either party - an impartial expert.

Qualification - In patent cases in particular, the expert witness will be called upon to give evidence as to what a person skilled in a particular field would know and understand. The expert’s opinion is only relevant if the expert has knowledge in that field. It is therefore important to ensure the expert is qualified in the field, not an associated field. For example, in a narrow field such as collapsible structures, not just a mechanical engineer but an engineer with experience with collapsible structures is required. Similarly, in trade mark cases the choice of expert depends upon the target market for the product.

It is also important to ensure that the expert is not over qualified. The relevant standard in Australia is that of the ordinary non inventive skilled worker. If the expert was a pre-eminent expert in the field at the priority date it is likely their knowledge and understanding went beyond what was known by the ordinary non inventive skilled worker. Any evidence by an overqualified expert on what was known may be given lesser weight.

As experts should be impartial and appropriately qualified it can be difficult to locate an appropriate expert. Australian universities have referral services which can be used to locate academic experts. Alternatively, enquiring of employees whether they know of a colleague who would be willing to give evidence can be a very effective way to locate an expert.

How is Expert Evidence Prepared
Once an expert is retained the time consuming process of obtaining their evidence begins. In Australia most evidence is given in written form. In order to prepare the written evidence it is necessary to confer with the expert at length to obtain their opinion. Having retained the most appropriate expert it is imperative that nothing is done during preparation to prejudice that evidence. It is important in obtaining evidence not to lead the expert to their conclusion, that is, not to indicate to them either expressly or by implication what evidence is preferred.

Recent case law has significantly affected how expert evidence must be prepared. In Minnesota Mining & Manufacturing Company v Tyco Electronics Pty Ltd the Court stated that “to give the patent to a prospective witness is tantamount to leading the witness” and very little weight should be given to that evidence. In light of this and following decisions all evidence as to the expert’s knowledge and experience must be obtained before they receive a copy of the patent specification.

Even more concerning is the implication of the recent Patent Office decision in Warner-Lambert Company v Cardinal Health Inc which held that the filing of a declaration in the proceedings amounted to a waiver of legal professional privilege which would otherwise render communications between the legal representatives and expert privileged from production. As such, all communications between the legal representatives and expert, including draft declarations, had to be disclosed to the other party. This is at odds with Court proceedings where written instructions to experts, but not draft written evidence, have for some years been subject to disclosure.

The danger of this increased transparency is that any instructions or amendments to the written evidence which lead the expert will be exposed, and the court or Office is likely to give little if any weight to the evidence stemming from those instructions. Extreme care must therefore be taken to ensure that any communication (including from the party to the expert) which leads the expert to their opinion is avoided. Where possible, communications with the expert should be oral so as to leave no written communications to be disclosed to the other party.

Of course, this recent change adds significantly to the time, effort, cost and complexity of expert evidence preparation. While this is not desirable, leading an expert during the preparation of evidence may result in little or no weight being given to their evidence, and the time and effort taken to prepare the evidence will have been wasted.

Expert evidence is usually the most important evidence in any case, and most particularly in patent cases. With the expected increase in disputes, and the heavier reliance on expert evidence, expected as a result of the Australia-United States Free Trade Agreement, good expert evidence will be of even greater importance than it has previously been.

Expert evidence has always been difficult, time consuming and costly to prepare but is becoming more so. Recent case law requires that much of the evidence be obtained before the expert can even be given a copy of the patent specification, and provides that all documents leading to the preparation of that evidence are available to the other party. Any correspondence which could be considered leading may severely damage the credibility and value of an expert’s evidence. However, even more so than before, good expert evidence can make a case and any additional cost and effort in correctly preparing the evidence can be more than repaid in the ultimate outcome. 

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