Vilca & Ors v Xstrata Ltd & Anor

Expert evidence is admissible only where the subject matter involves a sufficiently organised or recognised body of knowledge or experience, and the evidence can assist the court in resolving an issue. Evidence about general industry practice is not necessarily expert evidence. An emerging consensus is insufficient where no established, objectively ascertainable standard exists.

Where written principles are clearly articulated and the court can assess compliance with them without specialist assistance, expert evidence is unnecessary. A witness may nevertheless give relevant factual evidence about the genesis or development of those principles. Permission to amend pleadings and directions concerning reply evidence remain matters of case management.

This was a further case management conference in claims by Peruvian claimants against Xstrata Limited and Compania Minera Antapaccay S.A. The principal issue was whether the claimants should have permission to rely on Mr Bennett Freeman as an expert concerning the Voluntary Principles on Security and Human Rights, industry practice, and measures that could have reduced the risk of harm during a demonstration.

The court also considered permission to re-amend the Particulars of Claim and the defendants’ proposed provision for reply statements from factual witnesses.

1. Expert evidence. The application to rely on Mr Freeman as an expert was refused. The applicable principles require a recognised expertise governed by recognised standards or an accepted standard of conduct, together with sufficient experience to make the evidence potentially valuable. The evidence must also be reasonably required to resolve the proceedings under CPR 35.1 and requires permission under CPR 35.4.
2. The court applied the reasoning in Kesabo v African Barrick Gold [2014] EWHC 4067 (QB). There was no established consensus or objectively ascertainable standard concerning the appropriate response to the type of demonstration in question. Any emerging consensus went to possible factual evidence or the weight of evidence, not to the existence of a recognised expert discipline.
3. The Voluntary Principles were clearly articulated and materially unambiguous. The trial judge could determine whether the defendants had followed them, and whether any failure amounted to a breach of duty under English or Peruvian law, without expert opinion. Mr Freeman might give relevant factual evidence about the genesis of the Principles, but not opinion evidence about what the defendants reasonably should have done or the likely causative effect of particular measures.
4. Permission was granted to re-amend the Particulars of Claim in accordance with the current draft, subject to the procedure stated for communicating and resolving further amendments.
5. The defendants’ application to include provision for reply statements from factual witnesses was adjourned. It was better considered at a later case management hearing or pre-trial review after the factual witness statements had been served.

First-instance case management ruling. The judgment refers to earlier rulings in the same litigation, including [2016] EWHC 389 (QB), [2016] EWHC 946 (QB) and [2016] EWHC 1824 (QB).