#17754 - Causation And Remoteness - Tort Law

Causation and remoteness in negligence

General rule: C must prove on the balance of probabilities that the damage for which C seeks a remedy was caused by D’s negligence.

2 elements to causation: factual causation (‘but-for’ test or D’s negligence ‘materially contributed’) and legal causation (no breaks in the chain of causation).

NB: most authorities and textbooks break down the causation requirement into (i) causation, (ii) remoteness. ‘Scope of duty’ or ‘scope of responsibility’ can be included in the former requirement.

DAMAGE

Hunter v Canary Wharf (1996, UKHL) – physical damage = a physical change in the land which makes it less useful (a nuisance case).

Rothwell v Chemical & Insulating Co (2007, UKHL)

• FACTS: C’s employer D exposed C to asbestos; C developed symptomless pleural plaques which were themselves harmless, but signalled the presence of asbestos fibres in the lungs which might in turn cause fatal diseases; C resultingly developed clinical depression

• The symptomless plaques were not actionable damage. “The important point was that, save in the most exceptional case, the plaques would never cause any symptoms, did not increase the susceptibility of C to other diseases or shorten their expectation of life. They had no effect upon their health at all. Neither the risk of future disease nor anxiety about the possibility of that risk materialising amounted to damage for the purpose of creating a cause of action.”

Dryden v Johnson Matthey (2018, UKSC) – ‘personal injury’ = a physical change making the sufferer appreciably worse off (than he would have been had D not acted negligently) in terms of his health or capability to enjoy ordinary life (even if that change was hidden and symptomless).

Gemma Turton, ‘Risk and the damage requirement in negligence liability’ (2011) 35 Legal Studies 75

• Risk cannot coherently be recognised as damage.

• “In this paper, it will be argued that under the Barker apportionment approach, the gist of the negligence action is still the physical harm rather than the risk of that harm. Moreover, in the absence of physical harm, pure risk cannot be regarded as damage for the purposes of the negligence inquiry. The paper examines the notion of risk and distinguishes it from the related concept of probability. It will be argued that risk, properly understood, is a forward-looking concept that is incompatible with the role in which it is cast by Lord Hoffmann in the backward-looking causation inquiry. This paper will also question the moral significance of risk as damage, and explore the difficulties of explaining why risk might be considered deserving of compensation. It will be argued that the primary obstacle to accepting risk as damage in negligence is that risk is already addressed under the heading of breach of duty. If risk were to be recognised as actionable damage, the result would therefore be to subsume the damage requirement into the breach inquiry, effectively transforming negligence liability from a system of corrective justice to a punitive system focused solely on the defendant’s wrongdoing in isolation.”

• Fairchild – uncertainty about how asbestos caused mesothelioma material contribution to risk was sufficient for causation; based on a policy concern to avoid unfairness to innocent claimants facing an evidentiary gap.

• Barker v Corus – B had also exposed himself to asbestos during a period of self-employment; UKHL accepted C’s argument that while Fairchild applied, liability for the mesothelioma should be apportioned rather than being joint and several (calculated according to the individual’s contribution to the total risk of mesothelioma) thus, Barker ruled for an apportionment approach to liability (a.k.a. aliquot liability), contrasted to Fairchild’s joint and several liability – this was to “smooth the roughness” of the outcome under Fairchild where a defendant who cannot even be proved to be a but-for cause of the claimant’s injury is to face joint and several liability (as opposed to just several). This supposedly reached a fair balance between the interests of innocent claimants and potentially ‘innocent’ defendants (in that their negligence may not have caused any damage).

  • Lord Hoffmann (leading judgment) … reasoned that if it is only possible to prove that D’s negligence materially contributed to the risk of mesothelioma, then it is appropriate to regard the risk, rather than the mesothelioma, as forming the gist of the negligence action”. He reasoned that it does not matter that mesothelioma is indivisible, since “[c]hances are infinitely divisible and different people can be separately responsible to a greater or lesser degree for the chances of an event happening” since risk is divisible damage, it attracts several liability, and thus an apportionment approach. Lord Hoffmann criticised the CoA’s approach (joint and several liability) because it supposed that D’s breach of duty, which caused one phenomenon (increase in risk of harm), could result in him being liable for the whole of the ultimate injury – a whole other phenomenon.

    • Approved in Lord Phillips’ dissenting judgment in Durham v BAI –

      • BUT the majority of the UKSC in Durham v BAI disagreed and held that the actionable damage was the mesothelioma. UKHL in Rothwell held that, in the absence of mesothelioma materialising, the risk of mesothelioma is not actionable damage.

  • Baroness Hale instead clearly stated that the damage forming the gist of the action was the mesothelioma.

• Criticisms relating to the nature of the negligence inquiry:

  • Lord Hoffmann’s apportionment-based approach ostensibly appears to chime with negligence as a corrective-justice based system of liability, but on closer inspection this is not true. Two reasons:

    • AUTHORITY: “First, the continued insistence that the claimant must have developed mesothelioma [e.g. in Durham v BAI and Rothwell] undermines the claim that the gist has been changed to the risk of mesothelioma. In other words, the damage for which the claimant was compensated was still the mesothelioma itself, but liability was apportioned to reflect the degree of uncertainty surrounding proof of the causal link.”

    • CONCEPTUAL: “Secondly, even if the courts were to abandon the requirement that the claimant must suffer the physical harm, exposure to risk cannot be considered to be damage within corrective justice, because it adds nothing to the breach inquiry. Conduct is characterised as wrongful if it exposes the claimant to an unreasonable risk of harm. Corrective justice does not punish this wrongful behaviour, but requires the wrongdoer to repair the damage when his wrongdoing causes harm to another. If a defendant commits a wrong by exposing a claimant to an unreasonable risk of harm but this risk does not materialise, then he is not liable because there is no damage for him to correct. If the law was to hold that exposure to risk does constitute harm, then the requirement of damage would effectively be lost and the basis for liability would not be corrective justice but a retributive form of justice.”

• Criticisms of Barker relating to the nature of risk:

  • Steele explains that ‘risk’ and ‘probability’, “though related, are distinct terms”.

    • Turton builds on this, explaining that “while probability may be used to analyse past events, risk is a forward-looking concept. It describes a situation of uncertainty as to whether a particular outcome will occur. When a risk materialises it causes an outcome, so it is no longer a ‘risk’ but a cause.” – yes, there may be uncertainty as to which risk(s) materialised (and probability can help with that causation analysis), but it would be circular to say that if a risk has materialised it has contributed to the risk of the outcome. “In other words, a ‘risk’ is only a ‘risk’ while the outcome is still prospective. Once the outcome occurs, then the relevant question is whether the risk materialised and made a causal contribution.”

      • Weekes: “A risk which is proven to have resulted in damage is of course a risk that has been realised, or more properly, ‘a cause’.”

  • Turton argues that what Lord Hoffmann’s apportionment-based approach “actually achieves is to make the defendant liable for the mesothelioma itself, but to discount the extent of his liability to reflect the uncertainty over whether the risk he created was the risk that actually materialised. The method used to calculate the appropriate discount is the probability that it was the defendant’s risk rather than another source of risk that materialised. It cannot be the case that exposure to risk is the damage that is being compensated here, because risk is forward-looking and only exists before the outcome occurs. After the outcome has occurred, the risk that the defendant created either is or is not a cause of that outcome.”

    • Thus, the apportionment-based approach to liability is not actually compensating for risk, but rather to reflect the probability that the defendant caused the mesothelioma.

      • If it were based on risk, then D’s liability would be fixed from the time of his conduct – but the fact that liability varies (decreases) with every person who subsequently contributes to the risk, it must be based on probability of D’s risk being the one that materialises.

  • Thus, ‘material increase in risk’ or ‘material contribution to risk’? (where ‘risk’ refers to ‘total risk’)

    • I.e. whether risk should be measured in absolute or comparative terms, respectively.

    • ‘Material increase in risk’ does not change with subsequent additions of risk, but ‘material...