Couldyoupleasegive anoverviewofwhat is understoodby ‘clean’ and ‘dirty’ experts and the role theyplay in litigationand arbitration? The term ‘clean’ expert refers to an expert witness who provides evidence in the form of their impartial opinion on an issue in dispute where they have particular expertise or special knowledge (e.g. technical issue, quantum, delay). A clean expert’s primary duty is to assist the court or arbitration tribunal on matters relevant to their expertise. The term ‘dirty’ expert refers to an adviser engaged by a party to a dispute to provide technical advice on the strategy and preparation of its case. The dirty expert need not be impartial, and their duty is to act in the interest of their client. The dirty expert’s role may encompass a wide scope of services: • Technical advice on claims and case strategy, working together with a party’s lawyers. • Advice on identifying and compiling the relevant evidential records that need to be kept to support a claim. • Assisting in the drafting of technical aspects of the pleadings. • Preparing the technical aspects of claim narratives, analysis and calculations to a litigation or arbitration standard to support and demonstrate a party’s claim. • Objective assessments on the merits of the case. • Periodic auditing of costs or monitoring of progress and delay on disputes where the project is still is in progress. • Attending and assisting in negotiations to settle a dispute and other informal dispute resolution processes. Essentially, the dirty expert can form a bridge between the client and lawyers on legal and technical aspects of the dispute. What sortsof disputes warrant theuseof adirty expert? In my experience, dirty experts are normally engaged on large and complex construction disputes. Over the last 15 years, Australia has experienced many huge disputes on oil and gas, power and process plant projects, where it has not been uncommon for the amounts in dispute to run into the hundreds of millions or even billions. Such disputes have invariably involved complex claims for delay or disruption or massive cost overruns on messy termination cases. Delay and disruption claims arising from a plethora of events are notoriously difficult to demonstrate. Preparation of such claims often involves complex analysis and methodologies which require specialist expertise often beyond a party’s own inhouse capabilities. As result, delay and disruption claims are sometimes so poorly prepared by the in-house team that the ‘clean’ expert is left to make the client’s claim for them. Hence, ‘dirty’ expertise is needed to prepare credible delay and disruption analyses to demonstrate the claim, together with sufficient evidence of causation. 65 AUG 2022 | WWW.LAWYER-MONTHLY.COM EXPERT WITNESS In my experience of terminated project disputes, the key is to appoint dirty experts as soon as possible so they can advise on the most efficient way to complete the project while mitigating loss, as well as keeping the right records to support the inevitable additional cost and demonstrate reasonableness. What are the inherent advantagesof engaging adirtyexpert inaddition toacleanexpert as a dispute strategy? There are several advantages in engaging a dirty expert in the right circumstances: • A dirty expert is not hindered by the strict ethical duties of a clean expert, because they are engaged to act in the interest of their client and will be involved in the formulation of the case strategy. • They will also have the expertise to provide technical advice to enable the legal team to prepare the best case from a technical standpoint. • The client’s in-house teammay not have the time or expertise to support complex or large disputes. • Time and money may be saved on the identification and compilation of relevant evidence. • Again, time and money may be saved on the expert evidence, if the dirty expert’s quantum or delay or technical analyses can be supported by the clean expert. • A dirty expert’s early advice on disputes where projects are still in progress can help the client mitigate costs and keep the right records and evidence. • The right clean expert with the necessary specialist expertise may only become apparent after the formulation of the case. Rules in Australia on privilege relating to communications between expert The dirty expert need not be impartial, and their duty is to act in the interest of their client.