"Take nothing on its looks; take everything on evidence. There's no better rule."

So wrote Charles Dickens in the exchange between Mr Jaggers and Pip in Great Expectations. This proved to be apposite in the case of Mitchell v Great Lakes Reinsurance (UK) Plc where our insurance litigation team acted for the insurers.

This case is of interest to insurance lawyers and to the insurance industry in the interpretation of 'sole cause' clauses in insurance contracts. The case involved a personal accident insurance policy and how the court should interpret policy wording entitling the insured to benefits if he was injured and that injury was the sole cause of death. Given the limited case law in the UK, the case drew on international jurisprudence.

At the end of the day, the Court of Session in Scotland has provided useful guidance on the interpretation of these clauses based on the medical evidence in the case concerned although at first instance it was tempted to reach the same conclusion even before the evidence had been heard.

The conclusion

In summary, the court has considered that in this context 'sole cause' should exclude situations where the insured had a pre-existing medical condition that contributed to the death to a sufficient degree. This is so even where that condition would not by itself have resulted in death at the same time. Whether its contribution is sufficient will depend on the medical evidence and the wording of the policy.

The circumstances

This case was brought by the executors of the late Walter McCann. Mr McCann was involved in a car accident and admitted to Aberdeen Royal Infirmary on 26 June 2006 with a fractured sternum and multiple rib fractures. Sadly, he developed pneumonia, his condition deteriorated, and he died a week later. A post mortem found the cause of death to be respiratory and cardiac failure resulting from the pneumonia.

The executors sought payment under Mr McCann's accident insurance policy. The policy provided cover to Mr McCann if he sustained "bodily injury which, within 52 weeks, [was] the sole cause of permanent disability, death or hospitalisation."

The medical reports before the court indicated that Mr McCann had pre-existing conditions (chronic obstructive pulmonary disease (COPD)) which prevented his body from coping with the pneumonia.

The insurers refused indemnity, on the basis that the bodily injury was not the sole cause of Mr McCann's death. They maintained that in the context of the policy concerned, the COPD was also a cause of death. The executors raised proceedings.

The journey to the evidence

Round one. A debate. Based on the pleadings and the available medical reports, and some facts admitted by the parties for the purpose of this first hearing, the case called for a preliminary legal debate before Lord Hodge in 2010: Walter Mitchell and Another v Great Lakes Reinsurance (UK) plc 2010 CSOH 59.

The executors argued that in the absence of a separate exclusion clause, the sole cause clause did not prevent the insured claiming indemnity, even where there were other contributing causes. At debate, Lord Hodge rejected this submission, drawing support from both the policy wording and previous case law. He concluded that for the policy to be triggered bodily injury had to be the sole cause of the death and for the purposes of the policy that bodily injury had to exclude diseases and degenerative processes such as suffered by Mr McCann before the accident, despite them not being terminal conditions.

At that stage the executors had also argued that the fractures were the proximate cause of death and the pre-existing conditions were merely part of the chain of causation. Lord Hodge also rejected this argument.

Background condition or co-operating cause: a matter of degree?

Lord Hodge decided that whether a medical condition is viewed simply as a co-operative cause or merely a background condition is a question of degree. He quoted with approval the judgment of the Supreme Court of Carolina in Penn v Standard Life Insurance Co (1912) 76 SE 262:

"When at the time of the accident there was an existing disease, which, co-operating with the accident, resulted in the injury or death, the accident cannot be considered as the sole cause or as the cause independent of all other causes."

Lord Hodge suggested that a distinction could be drawn between (i) an active disease or infirmity which is likely in its natural development to lead to harm and to contribute to death, disability or injury (e.g. a co-operating cause) and (ii) an underlying medical condition which the ordinary man would not characterise as a sickness or disease and which merely predisposes the insured to such outcomes on the occurrence of a traumatic event (e.g. a background condition). Lord Hodge considered the medical reports before the court and decided that Mr McCann's pre-existing COPD was a co-operating cause of his death and not a mere background condition. The claim failed.

Round two. Was further medical evidence needed?

The executors appealed the decision of Lord Hodge and a three judge bench of the Inner House of the Court of Session decided that he ought to have heard evidence from the medical experts before making his decision on the question of degree but did not challenge his legal reasoning. The case was sent back to the Commercial Court for a proof – a civil trial.

Round three. Evidence

The proof took place before Lord Malcolm in October and November 2012: Walter Mitchell and Another v Great Lakes Reinsurance (UK) plc 2013 CSOH 14. Medical evidence was heard.

The court heard from two consultant cardiothoracic surgeons and the consultant forensic pathologist who had carried out Mr McCann's post mortem. While the medical evidence confirmed the pneumonia was caused by the fractures suffered in the accident, Lord Malcolm agreed with Lord Hodge that Mr McCann's injuries were not the sole cause of his death and that policy cover was not triggered. He also quoted with approval the passage earlier from Penn. He referred to Mr McCann's pre-existing COPD, which prevented his body from coping with the pneumonia, as a co-existing cause of the death.

The previous case law

In their legal submissions, the executors sought to rely on the decision of the Privy Council in an appeal from the Supreme Court of Ontario: Fidelity and Casualty Company of New York v Mitchell [1917] AC 592. In that case, the plaintiff had suffered a sprained wrist in a fall, which also triggered a previously latent tuberculous condition in his arm, resulting in continuing disability. The insurers there were liable to pay out for:

"(1) bodily injury sustained during the term of 1 year from noon standard time of the day that this policy is dated, through accidental means (excluding suicide, sane or insane, or any attempt thereat, sane or insane) resulting directly, independently and exclusively of all other causes in –

(a) immediate, continuous and total disability that prevents the assured from performing any and every kind of duty pertaining to his occupation."

In their defence, the insurers stated that the bodily injury, though sustained in the accident, did not independently and exclusively of all other causes result in the continuing disability. The plaintiff in Fidelity was successful, but Lord Malcolm distinguished that case from Mr McCann's case. In Fidelity, the tuberculous condition which prolonged the disability was triggered by the accident. His bodily injury was a single cause with a double effect: spraining the tendons and inducing the tuberculous condition. Mr McCann's pre-existing conditions were not latent in the sense that the tuberculous condition in Fidelity was. They were already longstanding and advanced by the time of the accident.

Lord Malcolm also accepted that the insurers gained further support from two English cases: In Jason v Batten (1930) Ltd [1969] Lloyds Rep 281, the insurer was liable to indemnify if the insured should:

"sustain in any accident bodily injury resulting in and being - independently of all other causes - the exclusive direct and immediate cause of the ...injury or disablement of the insured person"

The plaintiff suffered a road traffic accident in which his only physical injury was minor bruising, but the stress of the accident precipitated a coronary thrombosis. He suffered from arterial disease before the accident and it was established that he would have had a coronary thrombosis within three years if the accident had not occurred. The Court held that there were two concurrent causes, the pre-existing arterial disease and the formation of the clot. The two causes were independent of each other, and the thrombosis would not have occurred on June 21, 1965 unless both had operated. The claim failed.

In Southampton Leisure Holdings -v- Avon Insurance [2004] EWHC 571 (QB) the insurer was liable to pay out for accidental bodily injury, defined as: "injury which... solely and independently of any other cause occasions the disablement of the injured person" A professional footballer (David Howells) sustained an injury in a match while playing for Tottenham Hotspur; as a result of which he would never recover sufficiently to play first team football again. However, he had a history of recurring knee injury. The court decided that the pre-existing knee problems were a concurrent proximate cause. Mr Howells' claim failed.

Sole cause clarified

This decision will be of assistance to insurance lawyers and the insurance industry in giving fresh guidance clarifying liability under policies providing cover where a 'sole cause' condition is included. Claimants may need to pause for thought, but Mr Jaggers would approve of the decision being reached after the medical evidence was heard.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.