Petroleum Company of Trinidad and Tobago Limited v Ryan and another

In environmental negligence and nuisance claims, ordinary causation principles remain applicable. A claimant must establish a causative link between the relevant emission and the injury before any evidential inference or special approach for competing causes can assist. Authorities concerning contribution to disease and exceptional causation do not bridge the complete absence of evidence that the alleged exposure caused the claimant’s condition. An appellate court may interfere with factual findings only where there is an identifiable error or the decision cannot reasonably be explained or justified. The court must distinguish between liquid seepage and gaseous emissions, and between the existence of an emission and proof of a harmful concentration.

The claimants, who lived near a disused oil well, alleged that hydrocarbon emissions from land controlled by the appellant caused pulmonary fibrosis and reactive airways disease. The High Court dismissed both claims. The Court of Appeal allowed them by a majority, holding that the claimants had established responsibility for hydrocarbon emissions and the medical causal link; Mendonca JA dissented.

The appellant appealed to the Privy Council. The issues were whether the Court of Appeal had been entitled to reverse the trial judge’s factual findings, whether the evidence established emissions capable of causing injury, whether the medical evidence established causation, and whether a more flexible approach to causation was available.

1. Appeal allowed. The High Court’s order dismissing both claims was restored. The claimants were ordered, subject to any submissions within three weeks, to pay the company’s costs before the Board and below.
2. An appellate court should interfere with a trial judge’s findings of fact only where there is an identifiable error, such as a material error of law, a critical finding without an evidential basis, a misunderstanding or failure to consider relevant evidence, or where the decision cannot reasonably be explained or justified: Henderson v Foxworth Investments Ltd [2014] 1 WLR 2600, para 67.
3. The Court of Appeal was not entitled to reverse the trial judge’s findings on emissions. The trial judge had distinguished liquid seepage into the soil from gaseous emanations into the air. Evidence of seepage did not establish a harmful concentration of gaseous hydrocarbons. The alleged inconsistencies in the judgment and the evidence about air testing did not amount to an adequate basis for appellate intervention.
4. The company’s failure to produce further evidence about its investigations did not shift the burden of proof. Any evidential gap should have been explored at trial, and the absence of evidence could not itself affirmatively support the claimants’ case.
5. The trial judge was entitled to conclude that the medical evidence did not establish that hydrocarbon exposure caused either condition. General references to hydrocarbons, a limited textbook reference to hydrocarbon pneumonitis, and evidence that the conditions had several possible causes did not establish causation on the balance of probabilities.
6. The causation authorities concerning competing causes of industrial disease—Bonnington Castings Ltd v Wardlaw, [1956] AC 613; McGhee v National Coal Board, [1973] 1 WLR 1; Wilsher v Essex Area Health Authority, [1988] 1 AC 1074; and Fairchild v Glenhaven Funeral Services Ltd, [2002] UKHL 22; [2003] 1 AC 32—provided no assistance where no causative link between the alleged exposure and the medical conditions had been established.

• Privy Council: Appeal allowed and the High Court’s order dismissing both claims restored.
• Court of Appeal of Trinidad and Tobago: Majority allowed the claims; Mendonca JA dissented.
• High Court: Rajkumar J dismissed the claims.