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The Art of the CPR-Compliant Report 5:50 Lena: Okay, so we’ve got the mindset down—independence is king. But eventually, that mindset has to hit the page. I was looking through the "Expert Witness CPR Part 35 Explained Guide," and it’s very specific about how these reports need to be structured. It’s not just a technical paper; it’s a legal document with very high stakes.
6:11 Miles: It is, and the first rule of "Report Club" is: Know your audience. Even though a solicitor is the one asking you to write it, the report is actually addressed to the court. That changes everything about how you write. You’re not trying to impress the solicitor with how much you support their case; you’re trying to help a judge understand a complex topic.
6:30 Lena: And according to Practice Direction 35, that means keeping it concise. No one wants a three-hundred-page dissertation on the history of economic theory if the case is about a specific contract dispute. The Tribunal is actually likely to set page limits now. You have to be "concise and confined to the issues in dispute."
6:49 Miles: Which is a real skill! It’s much harder to write a short, punchy report than a long, rambling one. You have to strip away the "lengthy background explanations" and get straight to the heart of the matter. The main body needs to be in "plain English." If you have to go deep into the technical weeds, the 2025 Direction says to put that in a technical annex. Keep the narrative clear so the Tribunal panel can actually follow your logic without a PhD in your field.
7:14 Lena: I think that’s a trap a lot of experts fall into. They think using big jargon makes them look more "expert." But the rules say the opposite. A truly competent expert can explain their reasoning in a way that a non-expert judge can grasp. You have to identify your assumptions, distinguish between facts and opinions, and—this is crucial—include a formal Statement of Truth and a Declaration of Duty.
7:39 Miles: That Statement of Truth isn't just a footnote. It’s a legal promise. You are stating that you understand your duty to the court and that you’ve followed it. If you sign that and it turns out you were knowingly biased or ignored key facts, you’re in serious trouble. The CPR 35 guide emphasizes that transparency is professional. You must include anything that affects your opinion, even if it challenges your conclusion.
8:03 Lena: That’s a really important point. If there’s a piece of data that doesn't fit your theory, you don't hide it. You address it. You explain why it’s there and how it fits into the bigger picture. That actually makes you *more* credible. It shows you’re looking at the whole puzzle, not just the pieces that make a pretty picture for your client.
0:27 Miles: Exactly. And the "Practical Guide to Instructing Expert Witnesses" makes a great point about the logistics of this. To write a good report, you need good materials. Solicitors are supposed to provide "indexed and paginated bundles." If you’re an expert and you get a box of loose papers, you can’t do your job. You need to insist on a structured set of facts. The 2025 rules even suggest that parties should try to ensure all experts are working from the same "underlying data."
8:46 Lena: It’s like a science experiment. You can’t compare results if everyone is using different ingredients. If the experts are arguing over the data instead of the *interpretation* of the data, the court’s time is being wasted.
8:59 Miles: Totally. And the report needs to be "coherently articulated." Especially in economic evidence, if you’re departing from standard approaches, you have to explain *why*. The Tribunal is going to give more weight to techniques backed by "well-established textbooks" or "peer-reviewed journals." If you’re using some brand-new, experimental methodology you invented in your garage, you better have a rock-solid reason for why it’s better than the industry standard.
9:24 Lena: I also noticed that the 2025 Direction says experts should take "personal responsibility" for their analysis. You can’t just say, "Well, my junior associate did the math." You are the one who will be cross-examined on it. You are the one whose name is on the judgment. You have to own every sentence in that report.
9:42 Miles: And that includes any changes. If you finish your report, send it off, and then three weeks later you realize you made a mistake or a new piece of evidence comes out that changes your view—you have a "continuing duty." You have to communicate that change to the court and the other parties immediately. You can’t wait until the trial to drop a bombshell that you’ve changed your mind.
10:00 Lena: But you can't just keep sending in "supplemental reports" whenever you feel like it, right?
10:05 Miles: No, definitely not. You need permission for that. The court wants to manage this process tightly. If you start firing off new spreadsheets and letters without permission, the Tribunal can just refuse to accept them. They might even hit the instructing party with "cost sanctions." So, the goal is to get it right the first time—be thorough, stay objective, and keep it clear.
10:26 Lena: So, the "Actionable Mandate" here for our listeners: When you sit down to write, imagine the judge is sitting across from you. Explain it to them, be honest about the flaws in the data, and make sure every conclusion you draw is tethered to a fact or a well-founded assumption.