Breaking the chain of causation: Jenkinson v Hertfordshire County Council


Kriti Upadhyay considers the recent High Court decision in Alun Jenkinson v Hertfordshire County Council [2023] EWHC 872

Since the decision in Webb v Barclays Bank and Portsmouth Hospitals NHS Trust [2001] EWCA Civ 1141, it has been seen as an apparently now established principle in personal injury claims, that later negligence in the form of alleged negligent medical treatment for the index injury does not extinguish the causative potency of the earlier tort or break the chain of causation, unless the medical treatment in question is so ‘grossly negligent’ as to be a completely inappropriate response to the injury inflicted by the defendant.  Mr Justice Baker in Jenkinson challenged this long-standing notion, and determined that there was ‘no logical justification or policy reason’ for there to be such a ‘Specific Rule’ as cited from Webb.

The facts

The Claimant put his foot into an uncovered manhole cover and sustained a bad fracture to his right ankle in December 2017. He required surgical treatment for his injury. He brought a claim against the Defendant local authority for negligence or breach of statutory duty under s41 of the Highways Act 1980. The Defendant Hertfordshire County Council (HCC) admitted liability, but put the claimant to proof on quantum and the extent of his injury. HCC said it intended to instruct its own orthopaedic expert.

While the report was awaited, and prior to the listed CCMC due to take place on 7 April 2022, the Claimant wrote to the court requesting an 8-week adjournment of the CCMC to allow the parties to review the case in light of the Claimant’s return to work, as well as HCC’s anticipated orthopaedic report. This request was refused by the court.

On 20 March 2022, the Defendant’s orthopaedic expert Mr Machin reported, and his report was disclosed to the Claimant later that month. The expert was of the view that although the surgical treatment had been appropriately recommended following an accurate diagnosis and a correct assessment of the Claimant’s injury, the surgery itself was performed negligently.

Crucially, Mr Machin concluded that, “had the initial surgery been carried out to the correct standard, then Mr Jenkinson, in all probability, would have been able to return to work within 3 to 6 months post injury. He would have returned to the same job with minimal restriction and whilst he would have experienced some minor stiffness and ache this would not have prevented him carrying out his normal activities.”

In fact, the Claimant went on to have six further surgeries over the next three years, and was left with a much poorer prognosis. At one point in his medical treatment, serious consideration was given to amputation.

At the CCMC, HCC renewed the Claimant’s proposal for an adjournment to take stock, indicating that it would be applying to (i) amend its Defence and (ii) join the relevant NHS Trust responsible for the allegedly negligent surgery as a co-defendant and/or defendant to a Part 20 claim. The Claimant resisted this suggestion, and the CCMC went ahead. Directions and a trial date for August 2023 were set without reference to issues that might arise if the Defendant went ahead with its applications.

HCC on 25 May 2022 applied to amend their Defence. This application was refused by District Judge Vernon on 26 September 2022. The Defendant appealed against that refusal, and the appeal was considered by Baker J.

At first instance

DJ Vernon directed himself that on the authorities:

“There is no rule of law that later negligence always extinguishes the causative potency of an earlier tort; and…

…In cases where alleged negligent medical treatment is given to address injuries sustained as a result of an earlier tort, only medical treatment so grossly negligent as to be a completely inappropriate response to the injury inflicted by the defendant should operate to break the chain of causation.”

He was particularly reliant upon the Court of Appeal decision in Webb v Barclays Bank and Portsmouth Hospitals NHS Trust [2001] EWCA Civ 1141. Readers will be familiar with that decision, which involved an employee of Barclays Bank who fell over a stone in their forecourt while at work. She injured her left knee, but then accepted an allegedly negligent recommendation from her long-term consultant (at Portsmouth Hospitals NHS Trust) to have an above-knee amputation. It was agreed that the Claimant should have been told that the amputation was the very last resort, and that the Claimant had other options. Barclays argued that the amputation and subsequent problems were not caused or contributed to by their negligence, but were solely due to the intervening negligence of the Trust, but they settled with the Claimant on terms that essentially covered both claims. The Court of Appeal was asked to determine Barclays’ contribution claim against the NHS Trust. They rejected the arguments put forward by Barclays, and concluded that the chain of causation had not been broken by the negligence of the consultant, on the basis that the doctor’s conduct was negligent, “but not grossly negligent”, and “did not eclipse the original wrong-doing.”

DJ Vernon in Jenkinson concluded that permission to amend their Defence should not be granted to HCC, because they had not shown that there was a real prospect, under the proposed amendment, of a finding at trial that the December 2017 surgery had been “so grossly negligent as to be a completely inappropriate response” to the initial injury caused by HCC. As a result, he did not exercise a discretion over whether to grant permission to HCC.

The decision on appeal

On appeal, Baker J had to consider whether (i) the ‘Specific Rule’ as derived from Webb in fact exists in the first place, or (ii) if DJ Vernon had been wrong to find that there was no real prospect of HCC satisfying the Specific Rule at trial.

In his decision, Baker J analysed not only the decision in Webb, but also other well-known cases including Rahman v Arearose Ltd [2001] QB 351, which was decided a month before Webb. This was a claim by a branch manager at a fast food restaurant, who was subjected to a vicious assault by two Black youths, which left him with a fracture of the orbital wall of his right eye, for which he was treated at University College London Hospital. The surgery was performed negligently, such that the bone graft impinged on the optic nerve resulting in permanent blindness in that eye.

The claimant’s employer was held liable for their negligence in respect of the failure to provide a safe place of work, while UCLH NHS Trust was liable for negligence in the surgery. That claimant was also left with complex psychological injuries, including PTSD largely in reaction to his right-eye blindness, a specific phobia of Black people of Afro-Caribbean ethnicity as a result of the assaults, and a severe depressive disorder of psychotic intensity with an enduring personality change, due to both the depression and the PTSD, which probably would not have developed but for the loss of sight. The NHS Trust in that case conceded that the negligent execution of the surgery, causing blindness, was something for which it had sole responsibility, and the employer had none: there was no attempt by the Trust to rely upon the ‘Specific Rule’.

The Court of Appeal in Rahman had to consider whether the employer should be held responsible for loss and damage beyond that which the claimant would have suffered if the eye injury caused by the Trust’s negligence had not occurred. Laws LJ concluded that, from the point of view of causation, there is no rule in English law that later negligence always extinguishes the causative potency of an earlier tort. The real question in these cases, according to him (at [33]), is “what is the damage for which the defendant under consideration should be held responsible. The nature of his duty… is relevant; causation, certainly will be relevant – but it will fall to be viewed, and in truth can only be understood, in light of the answer to the question: from what kind of harm was it the defendant’s duty to guard the claimant?… Novus actus interveniens… and the concept of concurrent tortfeasors are all no more and no less than tools or mechanisms which the law has developed to articulate in practice the extent of any liable defendant’s responsibility for the loss and damage which the claimant has suffered.”

Laws LJ concluded in Rahman that “there is nothing in the way of a sensible finding that while the [NHS Trust] obviously (and exclusively) caused the right-eye blindness, thereafter each tort had its part to play in the claimant’s suffering.”

Baker J in Jenkinson considered it surprising, that if the ‘Specific Rule’ existed, Laws LJ should consider the NHS Trust’s concession of sole responsibility for the right eye blindness and its consequences to be “inevitable and obviously correct” – even without a finding of ‘gross’ negligence. Baker J also noted that this was not a case where the NHS Trust took the point itself.

So where did that leave the Specific Rule? After a discussion of various cases and the commentary set out in Clerk & Lindsell, Baker J concluded (at [43]) that he could not rely upon the existence of the so-called ‘Specific Rule’:

“In my judgment, the Specific Rule does not exist as a principle of law defining a necessary ingredient of a novus actus defence in the context of medical interventions. It follows that… DJ Vernon misdirected himself.”

Baker J noted that without the constraint of the Specific Rule as a principle of law, “in my judgment there is a real prospect… of a finding that the claimant’s initial injury, admittedly the result of the defendant’s negligence, was so badly mistreated that the defendant ought not, in fairness, to be considered responsible for the consequences of that mistreatment.” The extent to which that finding, if it were made, would reduce HCC’s liability was not something that he needed to determine at this stage, but he noted that there was no suggestion that the Trust’s liability would be so minor as to justify avoiding the added complexity and expense of involving the Trust in the claimant’s claim.

Baker J went on to conclude that even if the Specific Rule does exist as a rule of law, he also disagreed with DJ Vernon’s conclusion on whether HCC had raised a real prospect of success at trial by reference to it. Baker J considered the expert evidence from Mr Machin, and considered that on that report (which of course might well be challenged by other expert evidence in due course), “it is realistically possible that his view, when explored as it can only be at a trial, may be held to amount to this, namely that whereas there was here a correct choice to recommend surgery and a correct view that surgery should be an open reduction and internal fixation, what was actually done amounted, in substance, to no such thing, but rather was a botched job… A fracture repair that fails within a few days, it might realistically be concluded after a trial, was not a fracture repair at all.”

Having thus rejected not only the existence of the Specific Rule but also DJ Vernon’s reasoning in respect of realistic prospects of success, Baker J allowed HCC’s appeal and determined that HCC should have been given permission to amend its Defence.


At first glance, Baker J appears to have comprehensively dismantled a long-standing principle of law. However, it may be too early yet to see the full consequences: is this High Court decision going to be treated as an anomaly? It is not yet known whether there is going to be a further appeal from Baker J’s decision, so watch this space. In any event, the principles surrounding contribution claims and apportionment as between defendants/co-tortfeasors remain otherwise well-established. However, it certainly looks like Baker J has opened the way for defendants to successfully raise additional causation arguments in cases where a claimant appears to have gone on to have negligent medical treatment following an initial injury caused or contributed to by the defendant.


Kriti Upadhyay

Call: 2011

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